chemical science – year 7 -...

“What’s the solution?” Chemical Sciences

Year 7

This unit has been developed to meet the needs of Year 7 teachers. It is currently in draft form. Any feedback via the Moodle is appreciated. http://dlb.sa.edu.au/pmssmoodle/

Primary Mathematics and Science Year 7 Chemical Science Unit Draft December 2011

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http://dlb.sa.edu.au/pmssmoodle/

Science: Year 7 Unit – Chemical Science “What’s the Solution?”

Australian Curriculum Achievement Standard

By the end of Year 7, students describe techniques to separate pure substances from mixtures. They represent and predict the effects of unbalanced forces, including Earth’s gravity, on motion. They explain how the relative positions of the Earth, sun and moon affect phenomena on Earth. They analyse how the sustainable use of resources depends on the way they are formed and cycle through Earth systems. They predict the effect of environmental changes on feeding relationships and classify and organise diverse organisms based on observable differences. Students describe situations where scientific knowledge from different science disciplines has been used to solve a real world problem. They explain how the solution was viewed by, and impacted on, different groups in society.

Students identify questions that can be investigated scientifically. They plan fair experimental methods, identifying variables to be changed and measured. They select equipment that improves fairness and accuracy and describe how they considered safety. Students draw on evidence to support their conclusions. They summarise data from different sources, describe trends and refer to the quality of their data when suggesting improvements to their methods. They communicate their ideas, methods and findings using scientific language and appropriate representations

Science Understanding Mixtures, including solutions, contain a combination of pure substances and can be separated using a range of

techniques

Science as a Human Endeavour Science and technology contribute to finding solutions to a range of contemporary issues; these solutions may

impact on other areas of society and involve ethical implications Science understanding influences the development of practices in areas of human activity such as industry,

agriculture and marine and terrestrial resource management People use understanding and skills from across the disciplines of science in their occupations

Science Inquiry Skills Identify questions and problems that can be investigated scientifically and make predictions based on

scientific knowledge Collaboratively and individually plan and conduct a range of investigation types, including fieldwork and

experiments, ensuring safety and ethical guidelines are followed In fair tests, measure and control variables, and select equipment to collect data with accuracy appropriate to

the task Construct and use a range of representations, including graphs, keys and models to represent and analyse

patterns or relationships, including using digital technologies as appropriate Summarise data, from student’s own investigations and secondary sources, and use scientific understanding to

identify relationships and draw conclusions Reflect on the method used to investigate a question or solve a problem, including evaluating the quality of the

data collected, and identify improvements to the method Use scientific knowledge and findings from investigations to evaluate claims Communicate ideas, findings and solutions to problems using scientific language and representations using

digital technologies as appropriate


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Links to General Capabilities

Literacy The interdependence of science and literacy is demonstrated throughout this unit as students engage in a variety of different literacies of science. The language and literacy demands specific to the study of science develop along with scientific understanding and skills. This unit provides opportunities for students to develop their literacy skills as they:

Engage in discussions and record their thinking, ideas and questions in journals Draw labelled diagrams Read texts and procedures Present their information in an appropriate visual or oral format Complete visual representations of their understandings

Numeracy Within this unit students engage in tasks involving practical measurement and the collection, representation and interpretation of data from investigations. This unit provides opportunities for students to develop their mathematical understanding in the following ways:

Discuss measurements used in the recipe? Discuss ratio and where would you use it? Convert to make larger quantities? E.g. enough for 20 people, 100, 1000 etc Measuring liquids with accuracy and precision Gathering, recording and presenting data from investigations (both primary and secondary data)

Information and Communication Technology (ICT) Competence Within this unit students information technologies are used to research a science concept and present their understandings. Communication technologies offer opportunities for the communication and sharing of students’ ideas and results both within and beyond the classroom. This unit provides opportunities for students to develop their ICT skills in the following ways:

Use digital photographs to present their understandings Use of computers for research purposes Presentation of information - flow diagram, separation toolkit

Critical and Creative Thinking Within this unit students are asked to pose questions, make predictions, solve problems through investigation, analyse and evaluate evidence and summarise information. Students plan and conduct practical investigations. Students are asked to think in new ways about observations of the world. This unit provides opportunities for students to develop their critical and creative thinking skills in the following ways:

Developing a separation toolkit Developing a strategy for separating different materials Presentation of understandings – flow chart and information poster

Ethical Behaviour Ethical behaviour is relevant to experimental science and the use of scientific information. Within this unit students apply ethical guidelines in the gathering of evidence, including, considering the implications of their investigation on others, the environment and on other living organisms. This unit provides opportunities for students to develop their ethical behaviour in the following ways:

Working as part of a team on an investigation Gathering evidence to support their claims Working safely with equipment


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Personal and Social Competence Within this unit students further develop their teamwork skills by working together, sharing ideas and discussing their work. They develop self management skills such as planning effectively, following procedures and working safely. This unit provides opportunities for students to develop their personal and social competence in the following ways:

Working together in teams to complete tasks such as filling in tables, organising and conducting investigations

Working with others to develop strategies to separate materials and then successfully present their results

Links to Cross-Curriculum Priorities Sustainability Sustainability is concerned with the ongoing capacity of the Earth to maintain life. It aims to reduce our ecological footprint while simultaneously supporting a quality of life that is valued – the ‘liveability’ of our society. Scientific understanding and scientific inquiry processes help students to appreciate how people forecast change and plan the actions necessary to shape more sustainable futures, including the design, construction and / or management of the physical and social environment. This unit provides opportunities for students to develop an understanding of sustainability in the following ways:

Investigation into a variety of separation techniques and how these may impact on society e.g. water filtration, recycling, wetlands, desalination plant


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Unit at a glance

Chemical Science

Phase

Lesson

At a glance

Lesson 1 Session 1 Thinking About Mixtures and Solutions

Session 2 Everyday Mixtures and Solutions

ENGAGE

Lesson 2 Making sherbet

To capture students’ interest and find out what they think they know about mixtures and solutions and how they can be separated

Lesson 3 Separation Around Us

To provide opportunities for students to explore separation techniques used in their everyday lives

Lesson 4 Exploring Separation

To provide hands on, shared experiences of different separation techniques.

EXPLORE

Lesson 5 Serial Dilution

To provide hands on, shared experiences of different concentrations of solutions

Lesson 6 Understanding the Key Words

To support students in their development of their understanding of the key words

EXPLAIN

Lesson 7 Separation Toolkit

To enable students to demonstrate their understanding of different separation methods.

ELABORATE

Lesson 8 Separating the Mess

To provide opportunities for students to demonstrate their knowledge of and ability to perform different separation techniques.

Lesson 9 Session 1 Practical Applications Session 2 Practical Applications

To provide opportunities for students to investigate real life applications of separation techniques

EVALUATE

Lesson 10 Demonstrating the Understanding

To provide opportunities for students to represent what they know about solutions, mixtures and separation techniques

ENGAGE

What’s the Solution? Lesson 1 Session 1: Thinking About Mixtures and Solutions

At a Glance: To find out what students think they know about solutions, mixtures and different methods of separation Assessment Focus: Diagnostic Assessment is an important aspect of the Engage phase. This lesson will elicit what students already know and understand about solutions and mixtures and possible ways to separate them. This allows teachers to take into account students’ existing ideas when planning future learning experiences. Assessment Opportunities: Diagnostic Assessment Participation in discussions Journal entries Completed questions

Science Outcomes: Students will be able to: Record their current understanding of mixtures, solutions, reversible and irreversible changes and

different separation techniques Literacy Outcomes: Students will be able to: Contribute to discussions Use written text to record their experiences and current understandings Session 1: Thinking About Mixtures and Solutions

Equipment for each student: A copy of Resource Sheet 1 – Mixtures and Solutions

Teacher background information

A pure substance is a substance that cannot be separated into other substances by any physical processes. It will have a constant chemical composition. Water and gold are examples of pure substances. Pure water (H20) is made up of 2 hydrogen atoms and 1 oxygen atom which are chemically bonded. This composition does not change. Pure gold (Au) only contains gold atoms. Pure substances are homogenous – they have uniform composition throughout the whole sample. Elements and compounds are both examples of pure substances.

Elements are pure substances that cannot be broken down into simpler substances. Some examples of elements are oxygen (O), hydrogen (H), helium (He), iron (Fe) and calcium (Ca).

Compounds are pure substances made up of two or more elements. Some examples of compounds are water (H2O), carbon dioxide (CO2), sodium chloride (salt - NaCl) These can only be separated into individual elements through a chemical process.

Primary Mathematics and Science Year 7 Chemical Science Unit Draft December 2011 6

ENGAGE

A mixture is when two or more substances are mixed together and there is no chemical change. Mixtures are substances held together by physical forces and not chemical ones. Each of the substances in a mixture keeps its original chemical properties. Mixtures can usually be separated back to the original components using a variety of techniques. Examples of mixtures include sand and water, a mixed salad, salt water, a bag of assorted nails etc. The composition of a mixture can be varied by changing the proportion of the substances that make it up. Solutions are also mixtures. A solution is a type of mixture where one substance is dissolved in the other. In solutions the substance that dissolves will, over time, become evenly distributed throughout. E.g a solution of sugar and water means the sugar is evenly distributed throughout the water. If we compare sugar and water to sand and water – both are a type of mixture. The sugar dissolves and is evenly dispersed throughout the water while the sand sinks to the bottom. The sugar and water mixture is a solution while the sand and water mixture is not a solution. Solutions can also be gases dissolved in a liquid such as carbonated water found in fizzy drinks. In this case, the carbon dioxide (CO2) is evenly distributed throughout the water, making it a solution. The bubbles that we see in fizzy drinks are not part of the solution; rather they are the carbon dioxide that has separated from the solution and been released as gas.

Scootle Links:

TLF ID L3198 – Elements, compounds, mixtures and solutions

TLF ID L5822 - Types of matter: pure substances and mixtures

TLF ID L5824 - Types of matter: compounds and mixtures

Preparation Photocopy Resource Sheet 1 for each student

Prepare a version of a TWLH chart

Literacy Focus: A TWLH chart is used to elicit beliefs and ideas about a topic before, during and after an investigation or experience. It includes four sections with the headings: What we Think we know, What we Want to know, What we Learned, and How we Know.


http://www.scootle.edu.au/ec/resolve/view/L5822

http://www.scootle.edu.au/ec/resolve/view/L5824

Lesson outline Key words: solution, mixture, separation, reversible and irreversible changes

1. Introduce the key questions: What are mixtures and solutions and why might they need to be separated? What techniques can be used in the separation process? Explain that these are the questions students will be focussing on throughout the unit. Put these questions on display and continually refer back to them whilst working through other activities within this unit.

2. Organise the students into groups of three and give each student a copy of Resource Sheet 1 –

Mixtures and Solutions. Explain to the students that you are attempting to find out what their current understandings around mixtures and solutions are. Ask each team to discuss their thoughts on the questions and then have them individually record their understandings on the sheet.

3. Meet together as a class to share some of the responses and complete the relevant sections of the

TWLH chart -What we think we know and what we want to know. At this stage it is not about having the correct understanding it is about identifying the students’ current understandings.

Teacher tip: If students are unclear about reversible and irreversible changes you may need to briefly revisit this idea as this idea is assumed knowledge from the year 6 science curriculum.

It would also be beneficial to incorporate these concepts into discussions throughout the unit as a way of revising previous learning and putting such learning into other contexts.


Matter: Mixtures and Solutions

N ame ___________________________ Date _________

Please record your individual responses to the following in as much detail as possible. What is a mixture?

What is a solution?

What are some of the ways mixtures can be separated?

What do you understand by the terms reversible and irreversible changes? Give some examples to support your thinking.


Resource Sheet 1

ENGAGE Session 2 – Everyday Mixtures and Solutions At a Glance: To capture students’ interest and find out what they think they know about solutions, mixtures and methods of separation. Assessment Focus: Diagnostic Assessment is an important aspect of the Engage phase. This lesson will elicit what students already know and understand about mixtures and solutions and possible ways to separate them. This allows teachers to take into account students’ existing ideas when planning future learning experiences. Assessment Opportunities: Diagnostic Assessment Participation in discussions Journal entries

Science Outcomes: Students will be able to: Use their current understandings to start identifying mixtures and solutions Engage in discussions about whether or not mixtures and solutions can be separated Begin to identify different separation techniques Literacy Outcomes: Students will be able to: Contribute to discussions around science Use written text to record their experiences and current understandings Session 2: Everyday Mixtures and Solutions

Equipment for teacher : PowerPoint presentation (this is the only equipment needed if you are showing the PowerPoint) OR A variety of different household liquids and powders (safe for students to use – see

preparation for further details) Clear plastic cups Two buckets – one is for the mixtures and solutions to be poured into; the other is for the dirty

cups

Equipment for the class: Class science journal (optional) TWLH Chart

Equipment for each student: Science journals


Teacher Background Information

ENGAGE Dissolve: When something dissolves it forms a solution in a solvent. When you add sugar (solute) to water (solvent) the sugar mixes with the water and a solution is formed. When the sugar enters the water the sugar molecules break away from the sugar crystal and dissolve into the solution of water molecules. The sugar and water molecules begin to mix. The two substances continue to mix with each other until the sugar is evenly distributed throughout the water and a solution is formed.

Sugar enters the water Water and sugar molecules Sugar is evenly distributed begin to mix

Sugar is made up of molecules. The forces between each molecule are weak forces while the forces within the molecules are very strong. This means that when sugar is placed in water the molecules separate from each other. The molecules themselves stay in tact. A molecule is a group of two or more atoms that stick together. When two hydrogen atoms combine with one oxygen atom we get a water molecule. All water is made of tiny water molecules. Not all substances dissolve in the same way. Some compounds such as salt (NaCl) are ‘ionic’ in nature. This means that when they dissolve, they break into ions (charged atoms or groups of atoms) rather than complete molecules. The water causes the sodium and chloride atoms from the salt to separate. It forms a solution containing separate sodium ions (Na+) and chloride ions (Cl-). When the process is reversed and the water is removed the sodium ions and the chloride ions rejoin to make a salt crystal. Preparation Organise access to the PowerPoint – ‘From This to This’. This PowerPoint can be located on the moodle - http://dlb.sa.edu.au/pmssmoodle/ under the chemical science unit OR you could bring in a variety of different powders and liquids from your kitchen cupboard. Eg milo, milk, water, soft drink, flour, cereal, rice, food colouring, vinegar, bicarb soda, cordial etc. If you are using substances from the kitchen to undertake this activity you will also need access to an empty bucket to tip out any mixtures and solutions when you have finished and a bucket to place the dirty cups into ready for washing.

Safety Note: You may need to complete a risk assessment on some of the materials you are using. Be aware of the potential hazard of vinegar being splashed into student’s eyes. If using vinegar ensure you have access to water.


http://www.whyzz.com/answer/detail/category/2/subcategory/46/qid/1145


ENGAGE

Lesson outline Key words: substance, mixture, solution, dissolve, separation, pure substance Using the PowerPoint

1. Revisit part of the key questions: What are mixtures and solutions? 2. Place the students in cooperative learning teams and then introduce the PowerPoint – “From This to

This” - to the class (title slide only) and ask them to brainstorm a list of the different mixtures and solutions that they use in their homes.

3. Move through the PowerPoint one slide at a time and ask students to make predictions in their cooperative learning teams about what they think will happen when the two substances are mixed. Are any of the substances they are using pure substances? Do they think mixing them together will result in a solution or a mixture? Could the two substances then be separated? Discuss predictions with students before moving to the next slide which shows the two substances when they are mixed together.

4. On completion of the slide show ask students to look back at the original lists of other substances used around the home that are commonly mixed together. Is there anything else they can add to this list? Share suggestions with the class and discuss which of these form a solution and which of these form a mixture? Which of them can be separated?

5. Update information on the TWLH Chart.

OR

Using the materials from the kitchen

1. Revisit part of the key questions: What are mixtures and solutions?

2. Place students in cooperative learning teams and let them look at the different substances you have brought in. Ask them to discuss which substances they think can be combined to make a mixture and which substances they think can be combined to make a solution. Are any of the substances they are working with pure substances? Have them record their thinking as lists in their science journals.

3. Meet together as a class group and ask students to share their predictions regarding mixtures and solutions. As students offer a suggestion about what may make a mixture or solution, combine those substances together to check their predictions. As a class discuss whether or not they think the mixture or solution could be separated and what strategies might be used.

Teacher Tips At this stage if you are using actual materials for this lesson it is suggested that you run the session as a demonstration only. You could ask individuals to come out and demonstrate particular combinations but students get plenty of opportunities to “use” the materials themselves at a later stage. This will alleviate the mess and the need for lots of materials at this early stage.

4. On completion ask students to think of any other examples of mixtures or solutions that could be found around the home.



Lesson 2: Sherbet

ENGAGE At a Glance: To capture students’ interest and find out what they think they know about solutions and mixtures and methods of separation. Assessment Focus: Diagnostic Assessment is an important aspect of the Engage phase. This lesson will elicit what students already know and understand about mixtures and solutions and possible ways to separate them. This allows teachers to take into account students’ existing ideas when planning future learning experiences. Assessment Opportunities: Diagnostic Assessment Participation in discussions Ability to follow a simple procedure Journal entries

Science Outcomes: Students will be able to: Use their current understandings to talk about mixtures and solutions Follow a simple scientific procedure Engage in discussions around science concepts and explanations Literacy Outcomes: Students will be able to: Contribute to discussions about the science behind the sherbet Use written text to record their experiences and current understandings Lesson 2: Sherbet

Equipment for the class: Class science journal (optional) Word Wall and Glossary

Equipment for each team: Role badges for Director, Manager and Speaker Each team member’s science journal Access to citric acid, bicarb soda and icing sugar Measuring cup and spoon Clean plastic cup for mixing Clean popsticks for tasting

Equipment for each student: Science journals Copy of the procedure (Resource Sheet 2)


ENGAGE Teacher background information

Sherbet fizz The ingredients in the procedure are listed under their common names. You may like to introduce students to the scientific names of some of these ingredients: Bicarb soda – sodium bicarbonate Icing sugar – sucrose Citric acid – citric acid (this is the acid that makes lemons and limes sour) When you initially combine the ingredients to make the sherbet you have created a mixture. There has been no chemical change and each of the substances has maintained its chemical properties. They will not react with each other while they are dry. The fizz from the sherbet occurs when an acid (citric acid) and an alkaline (the bicarbonate soda) combine with the saliva in the mouth. The water in the saliva allows the citric acid and the bicarbonate soda to dissolve. As they mix together to form a compound a chemical reaction occurs and they create a gas (carbon dioxide) in the form of lots of tiny bubbles. You are actually feeling the sensation of carbon dioxide bubbles on your tongue. These are the same bubbles that are in fizzy drinks. The icing sugar adds the sweetness to the sherbet; it is not part of the chemical reaction. Preparation Distribute the ingredients into smaller containers so all students have easier access. Lesson Outline: Key words: solution, mixture, dissolve, compound

1. Give each student a copy of the ‘Making Sherbet’ Resource Sheet 2. Take time to read through the procedure and check for student understanding. Discuss what is meant by 5 parts to 1 part. What will this look like?

2. Show the students the equipment and ingredients provided. Then allow them the time to follow the

procedure to make their own sherbet. 3. Engage in a whole class discussion around the sherbet:

Is it a mixture or a solution? What is the role of each of the ingredients? What would happen if you left one out?

4. Discuss what happens scientifically when the sherbet is placed on the tongue. Record discussion

points in journals. Literacy focus

A science journal is a record of observations, experiences and reflections. It contains a series of dated, chronological entries. It may include written tests, drawings, labelled diagrams, photographs, tables and graphs.

Teacher Tips Be prepared for a mess. Encourage students to initially follow the procedure and not just ‘mix’ things together. Provide students with a zip lock bag so they can take home any uneaten sherbet. This alleviates

the need for them to eat it all in one go.

Eating too much sherbet can make students feel sick.


Opportunities for Extension Are all three ingredients necessary? Ask students to predict what would happen if one of the ingredients were removed. This could be the focus of a class discussion or it could be investigated by students by making three different versions of the sherbet. (Each version with a different ingredient missing).

Possible Curriculum Links

Numeracy – Why didn’t the recipe include specific amounts? Or did it? How do you know how much of each ingredient to use? Discuss the concept of 5 parts to one. What might this look like? What measurements might you use? How much of each ingredient will you need? What is ratio and where else might you use it? How much of each ingredient would you need if you were making enough sherbet for 30 students? 100 students? The whole school?

Literacy – students could be asked to write: An explanation of what they think happens to the sherbet mixture when it is placed in the mouth. A recount of the lesson.


Making Sherbet

(Make sure you use clean, dry equipment)

INGREDIENTS

Icing sugar Citric acid Bicarbonate soda

Cup Measuring spoon / teaspoon Popstick for sampling sherbet PROCEDURE Add 5 parts icing sugar, 1 part citric acid & 1 part bicarbonate soda

Stir ingredients together

Place a small amount on your tongue.

After tasting you may need to make some changes. If it is too bitter add more sugar. If there isn't enough fizz you may need to add more bicarbonate soda or citric acid. (Make sure you only add small amounts at a time, remember you can always add more but it is very hard to take it away.)


Resource Sheet 2

EXPLORE Lesson 3: Separation Around Us At a Glance: To provide opportunities for students to explore separation techniques used in their everyday lives. Assessment Focus: Formative Assessment is an important aspect of the Explore phase. It involves monitoring students’ developing understanding and giving feedback that extends their learning. Assessment Opportunities: Formative Assessment Participation in discussions Initial classification of photographs Journal entries on different separation techniques Response to question

Science Outcomes: Students will be able to: Classify photographs according to different separation techniques using current understandings Engage in discussions around their understanding of different separation techniques Explain how different separation techniques help to find solutions to problems

Literacy Outcomes: Students will be able to:

Contribute to discussions about separation techniques Use written text to record their experiences and current understandings

Lesson 3: Separation Around Us

Equipment for the class: Class science journal (optional) Word Wall and Glossary

Equipment for each team: Role badges for Director, Manager and Speaker Each team member’s science journal Package of separation photos


Preparation The photos for this lesson are stored in the Chemical Science folder on the Moodle. There are both high and low resolution copies of the photos - http://dlb.sa.edu.au/pmssmoodle/ Organise enough copies of the separation photos so that each cooperative learning team has a set of their own to work with. Primary Mathematics and Science Year 7 Chemical Science Unit Draft December 2011 17


EXPLORE Lesson Outline: Key words: separation, filtering, decanting, evaporating, sieving, visual separation

1. Organise students into cooperative learning teams. Revisit the key question – ‘What techniques can be used in the separation process?’ Ask each team to consider their responses to this question.

2. Discuss the following question: What are some of the different processes you have used or seen used

to separate items? 3. Provide each team with a copy of the separation photos and ask them to work together to sort the

photos into different groups according to their own criteria. When they have sorted all the photos into groups have them record the criteria they used for sorting on a piece of paper and turn that piece of paper upside down and place it alongside the groups.

Teacher note: At this stage it is about students using their own criteria and being able to explain the reasoning behind their choices. There are no right or wrong ways to classify the photos.

As a form of assessment students could take digital photos of their classified photos and use these as a way of recording their prior understandings about separation.

4. Once all teams have finalised their classifications and recorded their criteria for classification allow students to walk around and view the groupings of others. They can look closely at the different groups that have been organised and try to work out the criteria used for classification. Once they think they know how the photographs were sorted they can turn over the piece of paper which has the criteria written on it to see if their thinking was correct.

5. Meet together as a class to discuss the different criteria used and the ways in which the objects

were grouped. What problems are solved by the different separation techniques? E.g. nets have been used to solve the problem of birds taking fruit from trees. The nets are used to separate the birds from the fruit.

6. Go through the photographs as a class group and create a list of the different separation techniques

that were represented.

Which of the photographs demonstrated a form of decanting? Sieving? Filtering? Visual separation? Magnetism? Other?

Which were hard to classify? Why? How did you finally decide where to put them? Can you think of any other examples that could have been used?

7. Have students answer the following question – “How has using these separation techniques made our

lives easier?” Record their current understanding and thinking in their journals. They can use examples from the photographs to support them in this process. Ask them to add information to the TWLH chart.


EXPLORE Lesson 4: Exploring Separation

At a Glance: To provide hands on, shared experiences of separation techniques.

Assessment Focus: Formative Assessment is an important aspect of the Explore phase. It involves monitoring students’ developing understanding and giving feedback that extends their learning.

Assessment Opportunities: Formative Assessment Participation in discussions Completion of record sheet (Resource Sheet 4) Journal entries

Science Outcomes: Students will be able to: Explore a variety of separation techniques Make predictions and observations Engage in discussions around different separation techniques and their understanding of what is

happening

Literacy Outcomes: Students will be able to: Contribute to discussions about separation techniques Use written text to record their experiences and current understandings Record observations and predictions in a table format

Lesson 4: Exploring Separation

Equipment for the class: Class science journal (optional) Word Wall and Glossary Bins for the removal of waste – one for liquid waste, one for solid waste and one for the collection of

dirty equipment Containers of sand, talcum powder, iron filings, marbles, salt, rice, flour etc Spoons – one or two per container Magnets – in a zip lock bag (see teacher tip) A variety of materials for filtering – paper towel, filter paper, muslin etc A variety of sieves with different sized holes Jugs of water Tweezers, tongs Information for each of the separation techniques (Resource Sheet 3). Cut into individual separation

techniques TWLH Chart

Teacher Tip: Place each magnet inside a zip lock bag or wrap them in a layer of glad wrap. This makes the removal of the iron filings from the magnet easier when the lesson is completed.

If you have access to ‘Flowers of Sulfur’ (local high school chemistry lab) this could also be used as it will float when mixed with water and can then be decanted. Risk assessment required.


EXPLORE Equipment for each team: Role badges for Director, Manager and Speaker Each team member’s science journal Container of base material – sand Plastic cups and plates (at least 6 of each) Paper towel for cleaning up spills A list of the different separation techniques available to them (Resource Sheet 3)

Equipment for each student: Science journals A copy of Resource Sheet 4


Decanting Decanting is when you separate a liquid from an insoluble solid by carefully pouring the liquid from the container leaving the sediment behind. E.g. draining vegetables, decanting wine to remove the sediment, separating sand and water, panning for gold. It is the density of the solid compared to the liquid that is the property that enables you to decant. The solid or denser particles sink to the bottom and the water can then be poured off. Visual separation Visual separation is when materials can be separated by hand due to the differences in size and appearance with other substances in the mixture. The substances are easily identified between each other and can be easily separated by hand. Eg. Separating rocks and leaves, marbles from sand. It is the colour, size and shape which is the important property used for this type of separation.

Magnetic separation Magnetic separation is when magnetic material is removed from a mixture using a magnetic force. The magnetic material is attracted to the magnet and leaves the other non magnetic substances behind. Eg separating paper clips from sand, metal materials from the recycling bins. It is the magnetic features of the material which enables it to be separated in this way.

Sieving Sieving is when you separate different substances by using a sieve. Mixtures of different sized particles are separated by passing the mixture through a device containing many small holes. The holes allow the smaller particles to pass through trapping the larger particles in the container. Sieving is generally used when you have a mixture with reasonable sized particles. Eg separating macaroni from water, removing lumps from flour. It is the size of the particles which is the important property when sieving.

Filtering / filtration Filtering is when you separate materials based on the size of the particles by passing the mixture through material (generally paper) which allows the smaller particles to pass through and traps the larger ones. Filtering is generally used in place of sieving when you are dealing with particle sizes that are much smaller and would easily pass through the holes in a sieve, Eg separating dirt from water, flour and water. It is the size of the particles which is the important property when filtering. Primary Mathematics and Science Year 7 Chemical Science Unit Draft December 2011 20

EXPLORE Evaporation Evaporation as a separation technique is a method in which water can be converted from its liquid form to its vapour / gas form. E.g. drying the clothes, separating salt and water, sugar and water, dirt and water. Although evaporation enables you to separate the two substances it does not allow you to capture the water. It simply leaves the residue behind. Chromatography and distillation are other forms of separation which are not being covered in this unit. The following links provide visual demonstrations of different separation techniques which could be used to support the learning. http://www.youtube.com/watch?v=cs6iJavFJiI – magnetic separation separating nails from wood chips http://www.youtube.com/watch?v=2yRWCanU0kM&feature=related – separating aluminium cans, steel cans, paper and plastic http://www.youtube.com/watch?v=-dljgJqj9H8&feature=related - separating waste materials http://www.youtube.com/watch?v=qZ0nNWODNTg&NR=1 – roll sand sifter Preparation

Photocopy Resource Sheet 3 and cut up into separate pieces. These pieces will be used as labels to identify the different equipment provided for each separation technique used in the exploration process. You will also need another copy of this page for each cooperative learning team. This copy does not need to be cut up.

Photocopy Resource Sheet 4. Students may need two copies of this page.

Teacher Tip: Resource Sheet 4 may be better photocopied as an A3 sheet as it will give the students more room to record their thoughts.

Organise equipment at the front of the classroom so it is easily accessible for all students. Place all the separation tools and equipment together under the appropriate heading. E.g. put all of the different sieves in the one spot along with the sieve information from Resource Sheet 3.

Place buckets / bins around the room so students have easy access for the removal of waste materials which will help keep their work spaces tidy. Clearly label the bins.

– One bin for liquid waste – One bin for solid waste – One bin to place dirty equipment for cleaning at a later time

Organise the substances the students will need into small containers that are easily accessible. Have

four or five containers of each substance so students can take them back to their desks, use what they need and then return what is left when they have finished with it.


http://www.youtube.com/watch?v=cs6iJavFJiI

http://www.youtube.com/watch?v=2yRWCanU0kM&feature=related

http://www.youtube.com/watch?v=-dljgJqj9H8&feature=related

http://www.youtube.com/watch?v=qZ0nNWODNTg&NR=1

Lesson Outline:

EXPLORE Key words: separation, filtering, decanting, evaporating, sieving, visual separation, magnetic separation

1. Organise students into cooperative learning teams and assign roles. Revisit the key unit questions - What are mixtures and solutions and why might they need to be separated? What techniques can be used in the separation process? Explain to students that they are going to be exploring different mixtures and solutions and looking for ways to separate them.

2. Provide each student with a copy of the lesson recording sheet (Resource Sheet 4) and model the

way the lesson will be structured. Ask the students to fill in the information about the first two substances based on the demonstration that you provide.

Teacher tip: You can use any substance as the base material. Use a substance that is readily available and easy to use. For this lesson we have chosen to use sand as the base material for students to work with. To help keep a clean work space and catch accidental spillages students can conduct their separation techniques within the lid of an A4 paper box or into the bottom of a low plastic container. Plastic ice cream containers are also ideal. That way if anything is spilt it can be easily contained and cleaned up.

Structure of the investigation using sand as the base material Teacher Demonstration

– Decide which of the available materials you are going to combine with the sand. Before combining the materials ask the students to complete the relevant section of the recording sheet. Then ask them to record what they think will happen when you combine the sand with the other substance (this is their prediction).

– Combine the two substances and let the students observe what happens. Ask them to record their observations on the recording sheet.

– Discuss the techniques available for separation with the class and then decide which of those they think may be best for separating the two substances and which of those would not help.

– Choose two of the different techniques and demonstrate how you would go about trying to separate the substances using these two techniques. Ask the students to record their observations of what happened as you go.

– Then get the students to make a decision, based on their observations, on which of the two separation techniques was the most effective. What evidence did they base their decision on? Record their thoughts on the recording sheet.

– Throw the liquid and solid materials into the identified waste bin and then place the dirty equipment into another bin for cleaning. It is important to talk with students about maintaining a clean, organised work space.


Students Investigation

EXPLORE

3. Once you have modelled the structure of the investigation explain to the students that they are now going to repeat this process by combining the base material with the other materials provided. Give them the time needed to work with their team to complete the table using the other materials.

4. When students have finished combining their base material with the other substances ask them to

meet with someone else from the class and share their responses. They can compare their responses and opinions about which separation technique works best for which materials and which separation techniques do not work. Repeat this process once more so that students have met with two other people to discuss their thinking.

5. Glue record sheets into journals and then meet together as a class to share questions, responses,

findings. Briefly look at the different separation techniques: What did it separate well? What did it have trouble separating?



Visual Separation When materials can be separated by hand from other

substances in the mixture due to the differences in size and appearance.

Magnetic Separation When magnetic material is removed from a mixture using

a magnetic force.

Sieving Separation of a mixture of different sized particles by passing

the mixture through a device containing many small holes.


Resource Sheet 3

Filtering Separation of a mixture of different sized particles by passing the mixture through material (generally paper) that allows the smaller particles to pass through and

traps the larger ones.

Evaporation When water is converted from its liquid form to its vapour form.

Decanting Carefully pouring the liquid from a container leaving the

sediment behind. Separating a liquid from an insoluble solid.

Primary Mathematics and Science Year 7 Chemical Science Unit Draft December 2011 25Resource Sheet 3

EXPLORING THE SEPARATION OF MATERIALS – Base Substance_________________________ Substance Prediction - What do you think will

happen when the two substances are combined?

Will the substances form a solution or a mixture? Explain your thinking

Separation techniques – Which two methods will you use for separation? Which do you think will work best? Why?

Results – Which method worked best? How do you know?

Record your observations




Resource Sheet 4

EXPLORE Lesson 5: Saturated Solution to Dilution At a Glance: To provide hands on, shared experiences of different concentrations of solutions Assessment Focus: Formative Assessment is an important aspect of the Explore phase. It involves monitoring students’ developing understanding and giving feedback that extends their learning. Assessment Opportunities: Formative Assessment Participation in discussions Recorded observations

Science Outcomes: Students will be able to: Engage in discussions around the dilution and concentration of solutions Follow a scientific procedure Use key scientific terms appropriately Literacy Outcomes: Students will be able to: Contribute to discussions Record their observations and thoughts in an appropriate format Lesson 5: Saturated Solution to Dilution

Equipment for the class: Class science journal TWLH Chart

Equipment for each team: 5 plastic cups Measuring cylinder 400ml of plain water ½ cup of salt Teaspoon Measuring cup or cylinder Food colouring

Equipment for each student: A copy of the procedure (Resource Sheet 5) Science journals



EXPLORE A solute is dissolved in a solvent. The solute is the substance to be dissolved and the solvent is the substance that does the dissolving.

A serial dilution enables you to make different concentrations of the same solution. You create a series of dilutions where each one is progressively weaker than the one before. The dilution at each step is constant.

In a mixture the components can be found in different proportions. Solutions are a type of mixture and can therefore be found in different concentrations from a concentrate through to a very dilute solution.

A dilute solution is a solution that only has a small amount of solute dissolved in the solvent. You can make solutions more dilute by adding more solvent.

A concentrated solution is where there is a high proportion of solute in the solvent. For example orange juice concentrate has had a lot of the water removed and needs this water returned to make the solution drinkable. The water is the solvent and the orange juice is the solute.

A saturated solution is a solution where the maximum amount of solute has been dissolved. There is no room for anymore of the solute. If you continuously add salt to water you will reach a point where no more salt will dissolve and the salt will start to settle on the bottom of the glass. This is a saturated solution. If you increase the temperature of the water it will allow more salt to dissolve but even that will eventually reach saturation point. A saturated solution is not necessarily a concentrated solution as it may be a solution that becomes saturated at a low concentration. When you combine cordial and water you are diluting a solution. The cordial is already a solution so when you place it in water you dilute it further. You increase the amount of solvent. Preparation

Photocopy Resource Sheet 5 so that there is enough for one per student.

Teacher Tip: If you want your students to explore saturated solutions then make sure you use salt in this activity. Adding food colouring to the solution will give the students a visual indicator of the dilution process.

This task can also be done using plain water and food colouring or plain water and cordial. If you use either of these two options you are not able to link it to saturated solutions.

Lesson Outline: Key words: solution, dilute, solvent, solute, soluble, insoluble, mixture, pure substances, saturated solution, concentrate

1. Organise students into cooperative learning teams and assign the necessary roles.

2. Make sure all teams have a plastic cup and easy access to salt in order to create their saturated solution. Ask them to place 150ml of water in their plastic cup.

3. Explain to the students that they are going to find out how much salt can be dissolved in 150ml of water. Have them predict how many level teaspoons of salt they think can be dissolved in 150ml of water.


4. Discuss what is meant by a level teaspoon and how will students know when no more salt will dissolve? Get the students to investigate how much salt will dissolve in the water.

EXPLORE

5. Compare results from the class and suggest possible reasons for any differences. (Inconsistencies in measuring – water and salt, stirred or not stirred, inaccurate counting). Explain to students that they have now created a saturated solution. Discuss briefly what is meant by a saturated solution. Is there any way that more salt could be added? Introduce the words solute and solvent. Identify the solute and solvent from the saturated solution they made. Place this solution to one side.

6. Read the instructions on the back of a cordial container and make a sample of cordial following the instructions precisely. Discuss what happens to the cordial when you mix it with the water. Is it a solution or a mixture? How do you know?

7. Ask them to organise themselves into a line according to the strength of cordial that they like to drink – very strong through to very weak. Engage in a class discussion about what is meant by the words very strong? How do you define strong cordial? How do you define weak cordial? What is meant by a concentrate? What other things may need to be diluted before use.

8. Ask students to discuss what is meant by the word dilute and how do you make solutions more or less dilute? Explain to the students that they are about to complete a serial dilution procedure using the saturated solution they made earlier. Discuss what they think this means and what they think they will have to do to complete the process.

9. Give each student a copy of Resource Sheet 5. Ask them to read through the procedure and identify parts they are not clear about. Discuss these sections. Read through the procedure with the class and then allow them the time to complete the procedure in their cooperative learning teams.

10. Ask them to photograph / record observations about each of the four cups and record their thoughts and observations in their science journals.

– What do they notice about each cup of liquid? – Can they work out what has happened mathematically? – What would the concentration of the next cup be if they continued the process?

11. Meet together to share responses and observations. Add any new information to the TWLH chart.

Teacher tip: Students can use a portable salinity meter (Refractometer) to measure the salt concentrations of the different solutions. Salinity meters (Refractometers) can be purchased for $70 from the DECS Science Equipment Scheme. Item number - Code: 21-070. www.bizgate.sa.gov.au/shop/decs/ They are easy to set up and students can clearly and easily read the concentration of salt in a solution.

Optional Link the lesson to the salinity levels of water. Collect some different water samples for testing. – Distilled water, tap water, sea water, bottled water, river water (from different locations) etc. How does the salinity level vary in different water samples? What are acceptable levels of salinity in our water?

Curriculum Links: Maths / Numeracy What is ratio? Can you create a cordial mix with a 1:1 ratio? What quantities of each substance would you need? What about a 1:2 ratio? 1:4? What is meant by one part cordial to three parts water?


http://www.bizgate.sa.gov.au/shop/decs/

Serial Dilution Procedure

Equipment 4 plastic cups 100ml of the saturated solution made earlier 300ml of tap water 100ml measuring cylinder Food colouring Procedure

Decant the liquid from the saturated solution made earlier and place 100ml of this liquid into the first plastic cup. Add four or five drops of food colouring. Stir.

Place 90 ml of tap water into each of the 3 other cups. This water

is the buffer water needed to total the solution back to 100ml

Take 10ml of the solution out of cup 1 and add it to a new cup (cup2) which contains 90ml of buffer in it. Stir the solution. This will dilute the solution concentration to one tenth of the original solution.

Take 10ml of the solution out of cup 2 and add it to a new cup (cup

3) which contains 90ml of buffer in it. Stir the solution. This will dilute the solution concentration to one hundredth of the original solution.

Repeat this process once more. The final cup should contain 100ml

of liquid.


Resource Sheet 5

EXPLAIN Lesson 6: Understanding the Key Words

At a Glance: To develop an idea of students current levels of understanding of the key words used in the unit and provide them with the opportunities to increase their understanding.

Assessment Focus: Formative Assessment is an important aspect of the Explain phase. It involves monitoring students’ developing understanding and giving feedback that extends their learning.

Assessment Opportunities: Formative Assessment Participation in discussions around the key words Visual representations of the key words

Science Outcomes: Students will be able to: Engage in discussions around the key science words of the unit Explain their understanding of the key words

Literacy Outcomes: Students will be able to: Contribute to discussions about key science words Create a visual representation of one of the key words

Lesson 6: Understanding the Key Words

Equipment for the class A copy of Resource Sheet 6 cut up into individual pieces TWLH Chart Access to science dictionaries and the internet


Preparation Photocopy the words and their definitions. Cut the page into words and definitions. You should have

44 pieces of paper.

Lesson Outline: Key words: separation, filtering, decanting, evaporating, sieving, visual separation, magnetic separation, solution, dilute, solvent, solute, soluble, insoluble, mixture, pure substance

1. Ask students to form pairs and then give each student one of the cut up pieces of paper. Be aware that you will have more words and definitions than the number of students in your class. You may wish to identify the more important definitions for your class or some students will need to have two words or definitions. (Make sure the pair does not get an immediate match when you give out the words and the definitions.) Ask the students to discuss the words or definitions that are on their pieces of paper.

– What do they think the word means? – When is it used? – What word from their learning best matches the definition they have?


2. Once they have had a discussion ask the students to find their matching partner. E.g. the student who has the word or definition that matches what they have in their hands.

EXPLAIN

3. When everybody has found their matching partner ask the students to discuss the word they have

and its meaning. Do they understand what it means? When is it used? Can they give some examples? If students are unsure allow some whole class discussion time for students to clarify their thinking.

4. Students then need to work with their partner to complete a visual representation of the word and

its meaning. Literacy Focus:

A visual representation is a pictorial way of representing the meaning of the word. This representation could be a diagram, a picture, a cartoon, an annotated diagram. It is a way of visually getting the message across.

5. Display the completed representations around the room and give the students the opportunity to

look at what has been presented by others by completing a gallery walk. Literacy Focus:

In a Gallery Walk students move from one exhibit to another, using the agreed focus to discuss / respond to the exhibits. It provides an opportunity for all work to be on show and students to see the variety of responses provided for the task.

6. This is an ideal opportunity for them to provide feedback to others around the work that has been

completed. As they are going around the room looking at the work of others get them to look carefully at each representation and identify how successful the representations are at getting the message across.

– Can you clearly work out what the word means from the visual representation? – What have they done well? – What could be done to improve the representation?

7. Students can record their thoughts on sticky notes and place these on the pieces of work. Each student could be asked to comment on one or two pieces of work.

8. Meet together as a class to share feedback and representations and update information on the

TWLH Chart.


Pure substance

A substance that cannot be separated into other kinds of matter by physical processes. It has a consistent colour,

taste, texture and composition. It is made out of the same particles.

Mixture

A combination of two or more ingredients, the particles of

which are separable and independent.

Sediment

Solid matter which settles at the bottom of a liquid.

Solution

A mixture made up of one substance that has dissolved into

another. The solution has the same physical state as the solvent.

Solute

A substance dissolved in another substance, forming a

solution.

Solvent

A substance, usually a liquid, capable of dissolving another

substance. The solvent is usually the substance that is present in greater proportion.

Dissolve

To form a solution in a solvent. When you add sugar (solute)

to water (solvent) the sugar mixes with the water and a solution is formed.

Filtrate

Material, especially liquid, that has passed through a filter.

Soluble

Capable of being dissolved in a solvent.

Element

Pure substances that cannot be broken down into simpler substances. Some examples are oxygen (O), hydrogen (H), iron (Fe)

Insoluble

When a substance will not dissolve in a particular solvent. For example iron filings will not dissolve in water. They are insoluble.


Resource Sheet 6

Filtering

Separation of a mixture of different sized particles using a filter, such as paper. The smaller particles pass through the

filter and the larger particles are trapped.

Sieving

Separation of a mixture of different sized particles by passing the mixture through a sieve containing many small

holes.

Evaporation

One method in which water is converted from its liquid

form to its gas form.

Dilute

A solution with a low concentration of the solute dissolved

in the solvent.

Concentrated

A solution with a high concentration of the solute dissolved

in the solvent.

Compound

A compound is made of two or more elements that are

chemically combined, always in a set ratio.

Suspension

A suspension is a mixture with particles of a solid that will

not dissolve.

Saturated solution

A solution where no more solute can be dissolved at a

constant temperature.

Decanting

Carefully pouring the liquid from a container leaving the

sediment behind. Separating a liquid from an insoluble solid.

Magnetic separation

When magnetic material is removed from a mixture using a

magnetic force.

Visual separation

When materials can be separated by hand from other

substances in the mixture due to the large differences in size / appearance.


Resource Sheet 6

EXPLAIN Lesson 7: Separation Toolkit At a Glance: To support students to represent their understandings of separation techniques. Assessment Focus: Formative Assessment is an important aspect of the Explain phase. It involves monitoring students’ developing understanding and giving feedback that extends their learning. Assessment Opportunities: Formative Assessment Participation in discussions Completed page for the toolkit

Science Outcomes: Students will be able to: Engage in discussions around different separation techniques Explain their understanding of the different techniques Literacy Outcomes: Students will be able to: Contribute to discussions Present an information page on one of the separation techniques Lesson 7: Separation Toolkit


Preparation Photocopy the blank example of a possible layout for a separation toolkit page to show students what

it could look like - Resource Sheet 7. Photocopy an A3 copy of Resource Sheet 9 and cut it into individual pieces. Have an A3 copy of

Resource Sheet 8 available to piece it back together on. This page has the title of each of the columns already in place for the students to use as a cue for the information they need to give.

Ensure the different types of separation techniques are available to be displayed around the room

once the brainstorm is completed (Resource Sheet 3). This page was used earlier in the unit.

Primary Mathematics and Science Year 7 Chemical Science Unit Draft D December 2011 35

Lesson Outline:

EXPLAIN Key words: (will vary according to the separation technique students choose to use) separation, filtering, decanting, evaporating, sieving, visual separation, magnetic separation, solution, dilute, solvent, solute, soluble, insoluble, mixture, pure substance

1. Brainstorm a list of the different separation techniques students can remember. What can they tell

you about each one? As they tell you different techniques and information about them find that information from the cut up pieces of Resource Sheet 9 and place it in the appropriate place on Resource Sheet 8. Work as a class to complete all sections of the blank sheet.

2. Place the names of the different separation techniques on individual pieces of paper and place these

inside an envelope. Students then choose a piece of paper from the envelope and this tells them the separation technique they are going to be working on.

– Students can be given time to negotiate swaps with other people – Students could choose the separation technique that interests them the most

3. Explain to the students that they are about to create a page of information for a separation toolkit.

Discuss the following: – What is a toolkit? – What things might you find in a toolkit? – What are some different types of toolkits? – What might you find in a maths toolkit? A mechanics toolkit? A chef’s toolkit?

Brainstorm the information that the students think might be relevant in a separation toolkit.

4. Create a list of information that the students must include in their toolkit page. E.g. – A photo of the different equipment you can use – An explanation of how it works – What sorts of things can be separated using this method? – What things cannot be separated? – When would you use this method? – What are the advantages / disadvantages to this method?

5. Show the students a possible way to present the information (Resource Sheet 7) and allow them the

opportunity to discuss other ideas for presentation that they may have.

6. Give students the time needed to complete their page for the separation toolkit. Each page could be presented the same way for consistency of information or students could be encouraged to develop their own presentation style.

7. Completed pages can then be put together to produce separation toolkit booklets or the pages can

be displayed individually around the room.


EXAMPLE OF POSSIBLE PAGE FOR SEPARATION TOOL

Visual sorting is …..

Visual sorting works best when…….

Visual sorting will not work when…….

These are some things that you can easily visually sort.

Photo(s) demonstrating the visual sorting separation technique

Some advantages of using this method. Some disadvantages of using this method.


Resource Sheet 7

Separation Technique

Definition

Property Used for

Separation

Example


Resource Sheet 8


Separation Technique

Definition

Property Used for Separation

Example

Filtration

To remove by the act of a filter

Solubility

Dirt and water

Sifting (sieving)

A simple and convenient technique of

separating particles of different sizes.

Particle size

Stones and sand

Decanting

Carefully pouring a solution from a container in order to leave the precipitate (sediments)

in the bottom of the original container

Density

Water and sand

Magnetic attraction

(Magnetism)

Attracted to a magnet

Magnetism

Iron filings and sand

Evaporation

To change from a liquid or solid state into

vapour

Solubility and vaporisation

Salt and water

Visual sorting

Sorting by colour, shape or size

Colour, shape or size

Rocks and leaves

Resource Sheet 9

http://en.wikipedia.org/wiki/Precipitate

http://en.wikipedia.org/wiki/Sediment

ELABORATE Lesson 8: Separating the Mess At a Glance: To provide opportunities for students to demonstrate their knowledge of different separation techniques and their ability to perform separations using such techniques. Assessment Focus: Summative Assessment of the investigating outcomes is an important aspect of the Elaborate phase. It involves monitoring students’ developing skills and understandings of the Science Inquiry Skills and the investigative process.

Assessment Opportunities: Summative Assessment Participation in discussions Journal entries Investigation planner Investigation results and conclusions Completed procedural text or flow chart

Science Outcomes: Students will be able to: Use their current understandings of separation techniques to solve a problem Create a scientific procedure / flow chart for others to follow Engage in discussions around science concepts and explain their thinking

Literacy Outcomes: Students will be able to: Contribute to discussions about the science behind their thinking Use written text to record their experiences and current understandings Lesson 8: Separating the Mess

Equipment for the class: Class science journal (optional) Equipment for different separation techniques – filter paper, water, magnets, containers, sieves, tweezers etc. Bins / containers to throw out liquid and solid waste as needed A container to place dirty equipment when finished Paper towel, cloths for cleaning mess TWLH Chart Materials for creating the mess – 1 kg of rice, 1 kg of salt, 2 bags of marbles, 1 kg of sand, 200

grams of iron filings (if you cannot get iron filings substitute another magnetic material e.g. paper clips)

Equipment for each team: Role badges for Director, Manager and Speaker An appropriate amount of the combined materials (See teacher preparation notes for details) Plastic cups / containers Access to water Plastic plates


ELABORATE Equipment for each student: Science journals Copy of investigation planner and recording sheet (Resource Sheet 10 and

11)

Teacher background information One strategy for separating the substances is as follows:

1. Remove the marbles by hand using visual separation as the technique. The marbles can then be placed to one side.

2. The iron filings can then be removed using the magnetic separation technique. (See teacher tip page 18) Move the magnet through the mixture numerous times and the iron filings will attach themselves to the magnet and then can be easily removed. The iron filings can then be placed to one side.

3. Use a sieve to remove the rice grains. The mixture may need to be sieved a couple of times depending on the size of the holes. The rice can then be placed to one side.

4. You are now left with a mixture of salt and sand. To separate these two substances add water to the mixture and stir it well. The salt will dissolve while the sand will settle at the bottom.

5. The water can then be decanted and filtered through filter paper. This should let the liquid through and leave any remaining sand behind. Place the sand to one side and leave it to dry.

6. You are now left with a solution of salty water. To separate the salt from the water pour the solution into a shallow dish (the shallower the better as it will evaporate more quickly). Leave the solution to evaporate. You should then be left with a small amount of salt.

Do not expect students to be able to separate back to the original quantities of each substance. The more of the original quantities they can get the better but it would be extremely difficult to get the original amount back.

The amount of salt returned is very small.

The more water you add to the salt / sand mixture the longer it will take to evaporate.

Preparation Organise the individual amounts of the substances needed for the task: marbles, sand, iron filings, rice and salt. The amounts given above are a guide only. You may wish to adapt or modify these amounts to suit the size of your class. Make sure you include a reasonable amount of salt as this is the hardest substance to separate. Ensure students have somewhere they can dispose of any waste materials in order to help them keep a clean work space. Provide a container for solid waste, one for liquid waste and one for used equipment.

Teacher tip: To help keep a clean work space and catch accidental spillages have students conduct their separation techniques within the lid of an A4 paper box or into the bottom of a low plastic container such as an ice cream container. That way if anything is spilt it can be easily contained and cleaned up. You can create a mixture using other household ingredients such as flour, sugar, stones etc. You will need to ensure that the substances can all be separated in some way. For example do not combine sugar and salt in this mix as it is not possible to separate the two using the equipment and techniques available.


Lesson Outline

ELABORATE Key words: separation, filtration, sieving, evaporation, magnetism, visual separation, solvent, solute, prediction, 1. Before the break that precedes the science lesson show the students the individual samples of the

different substances they will be working with after the break. – Salt, rice, marbles, iron filings and sand.

2. When the students go out to the break, combine the substances together into one pile on a table. This will provide the mixture that the students are required to separate. You will need to prepare enough mixture to ensure each team has enough to try a variety of procedures. One lot per team is probably not enough as things will go wrong and they may need to start again with a new batch.

3. When the students return explain to them that somehow all the substances got mixed together. The

lesson has now changed and what they will now have to do is work in cooperative learning teams, using their knowledge of the different substances and the different separation techniques to separate the materials.

4. Organise the students into teams and assign roles. Provide each team with a list of the materials that

are in the mixture and a list of the different separation techniques they have been working with over the last few weeks ( Resource Sheet 12)

5. Give teams time to discuss the processes they think they will use in order to return as much of the

original, individual samples as possible. Have them map out their thinking in their journals – this could be done as a flow chart or in any way the students’ choose. Then reorganise the class into different groups and have them share their thinking with others. This is an ideal opportunity for students to compare ideas, to challenge thinking and to put forward suggestions for improvements.

6. Students then return to their original teams and share any new ideas or thoughts that they may now

have that they think will improve the effectiveness of their separation plan. In teams have students complete the Investigation Planner (Resource Sheet 10). They need to develop a plan around the order that they are going to use to separate the substances.

Things to consider – What separation techniques will you use first? Why? – What will happen next? Why? – What will you do if something doesn’t work?

7. Before students begin to implement their plan discuss with them the things they need to consider in

order to keep a safe, clean work environment. – Clean up any spills immediately – Put away equipment as you finish with it – Complete the separation tasks with care – Use equipment safely and correctly – Be considerate of others

8. Teams can then begin to work through the processes they have developed to separate the substances.

Make sure the students are aware that they need to record the processes they used and what happened as a result of these processes at the end of each step (Resource Sheet 11). This becomes a vital link to the next part of this task.


ELABORATE 9. Students then use the information from the investigation results sheet to develop a written procedure around the separation of substances or a flow chart showing the processes used and the steps they followed.

– A procedural text is used to describe how something is done. It includes a list of materials needed to complete the task, and a sequence of instructional steps. It may also include annotated diagrams.

– A flow chart is a graphic organiser used to describe a sequence of events or the stages of a process. A linear flow chart arranges the information in one line and uses arrows to indicate the order in which to read the text.

10. Provide students with the opportunity to share their completed procedures / flow charts with other

class members. 11. Students then complete the following evaluation questions in relation to separating the mess.

– How successful was your procedure? Why? – What problems did you face? How did you solve them? – What would you do differently next time? Why? – What did you find challenging? – What surprised you?

12. Update the TWLH Chart

Teacher tip: If students have not been introduced to procedural texts or done any work around them, it is critical to give them time to deconstruct procedural texts in other contexts e.g. English lessons before attempting to write one for science.


Separation investigation planner

Name:_________________________________________ Date:_______________ Other members of your team:_______________________________________________

What are you going to investigate? Solve this problem

A group of substances have accidently been mixed together. Using your knowledge of different separation techniques and the properties of materials try and separate as much of each of the substances as possible.

What equipment will you need? Make a list of equipment.

What separation techniques are you going to use and in what order are you going to use them? Explain why. You could use a flow chart to help organise your thinking. Record some predictions. What will you do to ensure a safe working environment?


Resource Sheet 10

Separation investigation results

Name:_________________________________________ Date:_______________

Use this sheet to record each of the steps that were used to separate the materials. Be sure to also record the results of each separation and the level of success. (If you need more space use another sheet)

Step 1

Step 2

Step 3

Step 4

Step 5

Step 6

Step 7

Step 8


Resource Sheet 11

Separating the Mess


Resource sheet 12

Separation techniques you may use:

Magnetic separation – to separate using magnetic attraction

Visual separation – to separate by colour, shape or size

Filtering- to separate by using a filter

Evaporation – to separate by allowing a liquid to change from a liquid into a vapour / gas

Sieving – to separate using a sieve

Decanting – to separate by pouring the liquid from a container and leaving the sediment behind

Contained in the mess you will find: Sand Salt Rice Iron filings Marbles

ELABORATE Lesson 9: Session 1 Practical Applications

At a Glance: To provide opportunities for students to discuss how science and technology have contributed to finding solutions to a range of issues.

Assessment Focus: Summative Assessment of the investigating outcomes is an important aspect of the Elaborate phase. It involves monitoring students’ skill development and their understandings of the Science Inquiry Skills.

Assessment Opportunities: Summative Assessment Participation in discussions Written journal entries

Science Outcomes: Students will be able to: Discuss how science and technology have contributed to finding solutions to a range of issues

Literacy Outcomes: Students will be able to: Contribute to discussions Use journal entries to record their thoughts

Lesson 9: Session 1 Practical Applications

Equipment for the class: One clear container such as a small fish tank or a clear, large plastic bowl containing 4 or 5 litres of

water Catchment story labels – see preparation section Substances to represent each of the factors entering the river system – see preparation section 16 small containers to hold materials e.g. foam cups, polycarbonate vials

Vial covered by paper to hide the contents from students.

DECS Science Equipment Scheme. VIAL, clear polycarbonate, screw cap, 70mL, 44mm dia x 57mm high, pack of 50 Code: 60-236 $36 a pack

Teacher Background Information Water is a precious commodity and a requirement for life. It is essential to our survival. All of us living within water catchments contribute directly or indirectly to the degradation of our waterways often without realising the impacts that we make. This places many ecosystems under threat of pollution. Keeping our water safe for consumption involves science and technology working together to ensure the pollutants are removed. This involves the use of a variety of separation techniques. It is an excellent example of how science and technology have contributed to find solutions to an issue.


ELABORATE Preparation There are 16 land uses identified in the story. Adapt this to suit the size of your class. E.g. each land use could be assigned to two people.

Some land uses could be omitted if they are not relevant to your catchment area. You can also add extra land uses if they are of relevance to your local region. This is a decision that can be made at individual sites.

Organise one labelled container / vial for each of the things that are to be placed in the river during the story. See list below for substances. You do not need large amounts of each of the substances. Catchment Story Substances

Land Use

Ingredient

Power station

Vinegar (acid rain)

Herd of cattle

Thick muddy water

Fertiliser

Baking powder

Piggery

Thick muddy water

Grazing land

Salty water

Coal Mine

Vinegar (acid runoff)

Hobby farms

Yellow water / toilet paper

Fishing

Tangle of line

Water skiing

Vegetable oil

Park

Styrofoam, plastic etc

Tourism

Paper, plastic etc

Subdivision

Soil

Gardens

Baking soda (pesticide)

Roads

Vinegar (acid runoff)

Industry

Soapy water

Tannery

Red food colouring


Catchment Story labels (to be placed on containers)

Set 1

Power Station Herd of Cattle Farming Country

Piggery

Grazing Land Coal Mine Hobby Farms

Fishing

Water Skiing Park Tourism

Subdivision

Gardens Roads Industry

Tannery

Set 2

Power Station Herd of Cattle Farming Country

Piggery

Grazing Land Coal Mine Hobby Farms

Fishing

Water Skiing Park Tourism

Subdivision

Gardens Roads Industry

Tannery


Resource Sheet 13

Session Outline

ELABORATE Key words: separation, filtration, sieving, evaporation, magnetism, visual separation, solvent, solute

1. Introduce the concept that Australia is the driest inhabited continent and that water is a precious commodity that is essential to our survival. Ask students to think about a local waterway or river system (or one such as the Murray - Darling system that is an important waterway for a large proportion of Australians) Discuss how what they do in their lives may impact on a local waterway or river system.

2. Place the fish tank or clear large container containing four or five litres of water in the middle of

the class and explain that this represents the river.

3. Distribute the smaller containers amongst the class and explain to them that you are going to read a story and when their ‘character’ emerges in the story they need to empty their container into the ‘river’.

4. Read the story to the students, (Resource Sheet 14) stopping at the end of each section when a

character / land use is mentioned. At this point ask the particular student(s) to come forward and empty their container into the ‘river’.

5. Ask the students to get into small groups to discuss the following questions:

– What were they feeling / thinking as the different substances were being added to the water? – Do they think this is like a real situation? – What practices are in place / should be in place to ensure minimal pollution to our river systems? – How could the science they have been learning about contribute to the cleaning of the river? – What separation processes could be useful in this situation?

6. Meet together as a class to share thoughts around how the science of separation techniques and

mixtures and solutions links to the story they have just heard. What are some of the possible ways to ‘clean up the water’? After the discussion ask students to record their thoughts around the following - How has science and technology contributed to finding solutions to water pollution? What other possible solutions do you have to help this situation?


THE STORY OF A RIVER

This is the story of the travels of a very special river - our river - through its catchment. It begins in the higher parts of the catchment where the rain runs off the slopes and begins its long journey to the sea. In the valley below there is a power station which generates electricity for the region. It burns large quantities of coal and releases pollutant gases into the atmosphere.

These pollutants combine with moisture in the atmosphere to produce acid rain. Rainfall carries these acids back to the Earth's surface and can pollute the very source of the river. The water gathers momentum as it descends the slopes. The river continues its journey towards the sea through farming country where, recently, some crops were fertilised. Afterwards they were watered and the run-off into the river has brought with it some of the fertiliser.

The neighbouring farm is a piggery. Some of the manure from the pig pens washes into a drainage pipe which then empties into the river. On the other side of the river are grazing lands. There are very few trees remaining and in some of the lower parts of the pasture, the water table has risen because the trees are not using the water any more. This water brings the salts in the soil up to the surface making the land unusable. It also means that run-off from the land is salty and this threatens the freshwater organisms and animals in the river. A grazing herd of cattle feed on the vegetation on the banks. When heavy rains arrive the banks collapse into the river.

The coal mine, which supplies raw mineral for the power station, pumps water out of the river to clean its equipment and flush out some of the waste. This includes various acids which all drain back into the river. Slowly the river starts to wind its way through the outskirts of a major town. Out here there are a number of hobby farms. The houses here are not connected to a sewerage system but have their own septic tanks. Occasionally these tanks overflow and untreated sewage seeps directly into the river.

There are a number of people making use of the river around the bend. Someone is fishing on the banks. Unfortunately their line gets caught around a rock and is left in the water. Other people are water-skiing. Their boat needs a service and in the meantime its engine is leaking oil directly into the river. Another group of people is enjoying a picnic at a park overlooking the river. A gust of wind blows some of their rubbish off the table and down into the water.

Further downstream the river is being utilised for tourism. A charter boat is giving some people a scenic tour of the river. Drinks are for sale on board but not everyone uses the bins that are provided.

The river now starts to meander through the suburban part of the town. A new subdivision is being developed. Many of the trees have been removed and when it rains, the top layer of soil is eroded and contributes to the silting up the river. Most houses in the developed parts of the town have a garden. To keep those nasty bugs away the gardeners use a range of pesticides. At the end of the day the sprinklers are turned on to water the plants. The pesticides wash off into the stormwater drains and enter the river.

Primary Mathematics and Science Year 7 Chemical Science Unit Draft D December 2011 51Resource Sheet 14

People who have spent the day at work are now starting to drive home. The roads are choked with traffic. Oil drips out of many of these cars and sometimes they brake in a hurry leaving traces of rubber on the road. Every time it rains these pollutants are carried into the stormwater drains and straight into the river.

There is still some industry along the river here. It uses detergents to keep its production equipment clean. But sometimes, the dirty water is hosed out of the factory into the gutter where it disappears into a storm water drain. Once again, however, this water flows straight into the river. If there were phosphates in the detergent then it will cause excess algae growth in the river. When this algae dies and begins to rot, it uses up oxygen which animals in the water rely on. They may suffocate as a result.

Redevelopment is occurring on the opposite bank. Demolishers have discovered a few drums of something mysterious. They won't be able to sell these as scrap. Someone suggests emptying them into the river. Everyone agrees and the waste from the old tannery is released into the river, to the detriment of all the organisms and animals living in it.

With one final bend the river finally arrives at its mouth and flows into the sea. But look at what flows out with it!

Adapted with permission from Queensland Waterwatch – http://qld.waterwatch.org.au


Resource Sheet 14

ELABORATE Lesson 9: Session 2 Practical Applications At a Glance: To provide opportunities for students to investigate real life applications of separation techniques. Assessment Focus: Summative Assessment of the investigating outcomes is an important aspect of the Elaborate phase. It involves monitoring students’ developing skills and understandings of the Science Inquiry Skills and the investigative process.

Assessment Opportunities: Summative Assessment Participation in discussions Journal entries Oral presentation of research

Science Outcomes: Students will be able to: Engage in discussions around the application of different separation techniques Discuss how science and technology have contributed to finding solutions to a range of issues

Literacy Outcomes: Students will be able to: Contribute to discussions about their findings Research and organise information Deliver an oral presentation on their research findings Lesson 9: Session 2 Practical Applications

Equipment for the class: A3 pages for each industry Equipment for each pair: Individual science journals Copy of Resource Sheet 15

Teacher background information Wastewater treatment plants The purpose of wastewater treatment plants is to process wastewater so it is not dangerous to humans or the environment. Wastewater consists of a mixture of domestic sewage (waste from toilets, sinks, showers and washing machines), industrial waste and occasional run-off surface water which has made its way into the sewers. Treatment plants use several processes, both physical and chemical to treat the wastewater.

During the initial stages screens are used to remove the course solids such as paper and plastics. After this has occurred the flow of the waste is reduced to encourage sedimentation. Sedimentation occurs when the heavier particles settle due to gravity on the bottom of the tank. The settled solids are scraped from the bottom and the surface of the liquid is skimmed to remove any floating materials.


ELABORATE Bacteria and other microorganisms are then introduced. Some of the remaining solid matter is processed by these microorganisms to form clumps of material which can then be skimmed. The microorganisms are then removed from waste materials usually through sedimentation or filtration. Chemical processes are then used to remove any heavy metals. http://www.sawater.com.au/SAWater/Education/OurWastewaterSystems/Wastewater+Treatment+Process.htm Scootle Link: TLF ID L3103 – Explore a water treatment plant Desalination plant The desalination process removes dissolved salts and impurities from seawater and turns it into quality drinking water.

The most commonly used process for desalination is reverse osmosis. Reverse osmosis involves pushing sea water through very fine membranes at extremely high pressure. The membranes act as filters to remove the salt and impurities. http://www.environment.gov.au/soe/2006/publications/emerging/desal/index.html http://www.sawater.com.au/SAWater/WhatsNew/MajorProjects/ADP.htm http://www.waterforgood.sa.gov.au/desalination/the-adelaide-desalination-plant/ Water treatment plants For many years Adelaide relied on drinking untreated water from the River Murray. Water from South Australia’s reservoirs is now treated to improve the quality of our water and make it suitable for drinking. The processes involved in water treatment plants are the very similar to the processes that are used to treat wastewater.

Water undergoes a 5 stage cleaning process.

The first stage is known as coagulation and flocculation and is used to collect small particles and dissolved organic matter. This stage is a complex process where coagulants are added to the water. These coagulants react with the impurities in the water causing them to form larger particles up to 5mm in diameter. This is known as flocculation.

The second part of the process involves sedimentation. Once the water leaves the flocculation tanks it passes into the sedimentation basins where the water is left to settle. The floc settles to the bottom and forms a sludge which is later removed.

Once sedimentation has occurred the water is then filtered. It is passed through a deep bed of sand. As the water filters through the sand the particles left from the sedimentation process are removed.

When the water has passed through the filters it still needs to be made safe for human consumption. This is achieved by adding chlorine to the water to destroy any micro-organisms that were not removed through the previous processes.

After the water has had the chlorine added it is then stored in covered storage tanks ready to be distributed. http://www.sawater.com.au/SAWater/Education/OurWaterSystems/Water+Treatment+Plants.htm


http://www.sawater.com.au/SAWater/Education/OurWastewaterSystems/Wastewater+Treatment+Process.htm

http://www.environment.gov.au/soe/2006/publications/emerging/desal/index.html

http://www.sawater.com.au/SAWater/WhatsNew/MajorProjects/ADP.htm

http://www.waterforgood.sa.gov.au/desalination/the-adelaide-desalination-plant/

http://www.sawater.com.au/SAWater/Education/OurWaterSystems/Water+Treatment+Plants.htm

Recycling centres

ELABORATE Waste materials that are sent to recycling centres are separated in a variety of ways.

Visual separation – material that is large or easily recyclable is removed by hand, cans, bottles, plastics are separated by workers manually removing these items and placing them in different areas.

Other recyclables travel along sorting lines which is a process that uses a combination of machines and people to sort materials into specific areas. Different people have different responsibilities along this line.

Magnets are used to separate ferrous metals

http://www.wingfieldrecycling.com.au/

Wetlands Wetlands are an important way to help improve our water quality. Within the wetlands environment there are several different separation techniques at work.

Floating and semi submerged litter is separated from the water in one of two ways. It is either trapped by the trash racks (gross pollutant traps which operate like large sieves, allowing the water through but trapping the rubbish) or it is trapped by the plants growing within the wetland where it can later be removed by hand (visual separation)

As water moves slowly through a wetlands environment sedimentation occurs. This is where the heavier particles of mud and silt and other pollutants sink to the bottom of the wetlands. Due to this sedimentation sections of wetlands may need dredging over time.

http://waterwatchadelaide.net.au/index.php?page=how-does-a-wetland-work

http://science.howstuffworks.com/environmental/green-science/wetland.htm

Mining industry Magnetic separation is used to remove large ferrous metals that could be damaging to the production process. Items such as hand held tools, iron scrap, machinery tips, nails, wire, nuts and bolts are removed from the process. Magnets are suspended over conveyor belts as the ore is moved from one place to another.

The process of separating the desirable mineral from all the other minerals in the ore is known as ore dressing. The type of separation technique used is dependent on the physical or chemical property of the mineral. Some minerals are separated by density. This is called float – sink separation. The minerals are crushed and then placed into a liquid. The materials that are less dense than the liquid will float and those that are denser will sink.

Some minerals are separated because of their chemical properties. The mineral is crushed and then placed into a solvent. The ore dissolves and then is poured off in solution which leaves the unwanted minerals behind.

Some minerals are separated because of their particle size. These minerals are passed through sieves or filters to separate the desired mineral from the unwanted.

Froth Flotation is another process used in the mining industry for separating the desired minerals from the unwanted materials. Froth flotation takes advantage of whether or not minerals are attracted or repelled by water.

http://www.theajmonline.com.au/mining_news/news/2010/january/january-14-10/featured-products/magnetic-separation-for-the-mining-industry http://www.its-about-time.com/pdfs/mm56-65.pdf (page 8 and 9)


http://www.wingfieldrecycling.com.au/

http://waterwatchadelaide.net.au/index.php?page=how-does-a-wetland-work

http://science.howstuffworks.com/environmental/green-science/wetland.htm

http://www.theajmonline.com.au/mining_news/news/2010/january/january-14-10/featured-products/magnetic-separation-for-the-mining-industry

http://www.theajmonline.com.au/mining_news/news/2010/january/january-14-10/featured-products/magnetic-separation-for-the-mining-industry

http://www.its-about-time.com/pdfs/mm56-65.pdf

Salt industry

ELABORATE One method for the collection of salt involves separating the salt from the water. This process is known as the salt evaporation process. It can really only occur in warm climates where the evaporation rate is greater than the precipitation rate. Salt water is captured in shallow ponds and the sun then goes to work evaporating away most of the water. This leaves concentrations of salt behind. http://www.mortonsalt.com/saltfacts/salt_prodproc.htm

Preparation Organise 2 A3 pages with the name of an industry written across the top. You will need two pages for each of the industries mentioned on the previous pages – 7 industries in total. Have the different separation techniques on display for the students to see. – Resource Sheet 3 Lesson Outline Key words: separation, filtration, sieving, evaporation, magnetism, visual separation, solvent, solute,

1. Place one group of the A3 pages at different locations around the room. Ask students to move around the room recording what they think they already know about these industries on the sheet. Meet together as a class and create a list of commonalities that are found within these industries. Highlight the one important factor that the students will be investigating further – that all these industries use separation techniques as part of their processing. Can students think of any other industries that could be added to the list?

2. Distribute the remaining A3 pieces of paper around the room and then introduce the following

question to the class. How does the work we have been doing with mixtures, solutions and separation techniques link to these industries? Give students some time to process and think about this question and then give them some sticky notes to write on.

3. Ask students to move to one of the A3 sheets distributed around the room and to ensure that they

are roughly evenly spread. Once everyone is situated around a piece of paper ask the students to use their sticky notes to record as much as they can about that particular industry and its use of separation techniques. What do they already know and understand? What are the gaps? When they have finished with one industry they could then move on to another giving them the opportunity to record against all of the industries.

4. Meet together as a class and share some of the thinking. Students will then be asked to choose one of

these industries for further investigation.

Teacher Tip: Students could randomly choose their industry based on their own area of interest or to ensure all industries are covered they could choose an industry by taking a piece of paper with an industry written on it from a bag.

You may like to have all of the class investigating the same industry

You may like to allow students to work alone or in pairs of their choice.


http://www.mortonsalt.com/saltfacts/salt_prodproc.htm

5. Give students a copy of Resource Sheet 15. Give them time to read through the information and then allow time for questions and further clarification of the expectations. Work with the class to create a list of presentation requirements. What are you expecting will be included? What is optional?

6. Provide time for students to complete the research and present their information to the rest of the

class or a wider audience.

Teacher Tip: A rubric has been provided to help with the overall assessment of the key ideas and concepts of this unit (Resource Sheet 18). This rubric does not get into the specifics of presentations, flow diagrams and procedural texts. You may wish to develop your own rubrics to focus in on specific details for a more detailed assessment of the literacy components.

Opportunities for extension Students could engage in a debate relating to the development of a desalination plant. Students could be presented with a statement such as “Desalinations plants - securing Adelaide’s water future”. They could then research the pros and cons and then develop for and against arguments. Students could write letters to the editor based around their research into current practice in areas such as the significance of wetlands, desalination plants, recycling rubbish etc.


SEPARATION IN ACTION

Solutions, mixtures and separation techniques are an important part of our lives.

Many industries use the science and technology behind the different separation techniques as part of their daily processes.

http://www.flickr.com/photos/19779889@N00/3746214349/

You have been given an industry to investigate further. You will need to research your industry and the separation techniques it uses. Once you have completed your research you will need to organise a 2 minute oral presentation to present this information to the rest of the class.

Questions to direct your research and thinking:

– What is your industry? – What do they work with in terms of mixtures, solutions, pure substances compounds etc? – What separation techniques do they use? – How do these techniques help as part of the processes involved in the industry? – What issues are being resolved by the industry you have chosen? – Are there any negative impacts on society or the environment from the processes involved? – What is being done to overcome these? – What changes have happened over time within the industry with regards to the science and

technology involved? You may wish to develop some resources to support your presentation e.g. a poster, model, props, diagrams, photographs etc.

The key ideas you will need to consider when researching and organising this presentation are..

Explaining how science and technology have contributed to finding solutions to everyday problems

Giving examples of separation techniques used in people’s work and in industry

Explaining how these solutions may impact on other areas of society


Resource Sheet 15


EVALUATE Lesson 10: Demonstrating the Understanding At a Glance: To provide opportunities for students to represent what they know about solutions, mixtures and separation techniques and to reflect on the learning during the unit Assessment Focus: Summative Assessment of the conceptual learning outcomes is an important aspect of the Evaluate phase. It involves monitoring students’ developing skills and understandings of the science concepts

Assessment Opportunities: Summative Assessment Participation in discussions Journal entries Presentation of understanding in an appropriate form

Science Outcomes: Students will be able to: Engage in discussions around their knowledge and understandings of solutions, mixtures and separation

techniques Represent their understandings of science concepts in an appropriate format

Literacy Outcomes: Students will be able to: Contribute to discussions Use written text to record their understandings and present this information to others Lesson 10: Demonstrating the Understanding

Equipment for each student Individual science journals A copy of resource Sheet 17 Access to unit photographs if needed

Teacher background information Students will be asked to identify and represent as many links as possible between the key words that have been used throughout the unit. What follows is an example of a way in which the words could be linked and represented. This is not the only possibility and it is also not a completed example. It has been included to give you a sense of the possibilities and the intended outcome from this lesson.

Teacher Tip: Use Resource Sheet 16 as an example for the initial discussion only. Once students understand what is expected and how they could demonstrate their understanding remove the example. This will encourage students to develop their own representations rather than copy what someone else has produced.

REPRESENTATION OF UNDERSTANDINGS


Mixtures

When two or more ingredients are mixed together

Solution A mixture made up of one substance that has dissolved into another

Mixtures can be separated

Solvent A substance capable of dissolving another

+ Solute A substance dissolved in another substance

=

In a salt water solution the salt is the solute and the water is the solvent

Decanting When you separate a liquid from an insoluble substance. Give the insoluble substance time to settle and then pour the liquid off the top

Pure substance Something which cannot be separated into other parts

Soluble Salt and sugar are soluble. This means they dissolve in water and create a solution.

Distilled water is a pure substance. Water is a common solvent

Sieving Separating a mixture of different sized particles by passing the mixture through a sieve

Resource sheet 16

Key words to consider separation filtering sieving evaporation magnetic separation visual separation solvent solute solution

soluble insoluble decanting mixture pure substance saturated solution compound suspension dilute concentrated


Resource sheet 17

EVALUATE Lesson Outline Key words: separation, filtration, sieving, evaporation, magnetism, visual separation, solvent, solute, solution, soluble, insoluble, decanting, mixture, pure substance,

1. Revisit the key questions for the unit with the class – “What are mixtures and solutions and why might they need to be separated? What techniques can be used in the separation process?” Give students a copy of Resource Sheet 17 and explain to them that those words are going to be the focus of the lesson.

2. Ask students to find a partner and then get them to look at the words from the Resource Sheet

and choose two or more words that they think may be related to each other in some way. (See resource Sheet 16 for examples) Ask them to explain the link between the words and then look for other words that may link together.

3. Meet together as a class and share some of the thoughts. Ask the students to show how the words

mixtures and solutions can be linked together. Share some of these representations – using arrows and boxes to show the relationships.

4. Students need to create a representation (poster, mind map, visual representation, concept map)

that demonstrate their level of understanding of the key words and the way these words link together and are interrelated. (see Resource Sheet 16 for an example) Students may develop their own way of representing the information. It is the content that is important. How well do they show their level of understanding of the concepts involved?

5. Discuss with students what the key elements are. E.g. what is needed for the task to be completed

successfully? Provide students with an appropriate amount of time to complete the task.

6. Prepare a visual display of the different representations so the students can see what others have produced.

7. Ask students to then record their responses to the following:

a) What are mixtures and solutions and why might they need to be separated? b) What techniques can be used in the separation process? Give an example of each. c) Explain how science and technology have contributed to finding solutions to everyday problems

with regards to chemistry and the separation of materials. Give examples.



Link to Learning

Beginning Achieving Advanced

Science Understandings Explains what is meant by pure substances, mixtures and solutions

Attempts to explain the meanings but lacks clarity and detail

Clear explanations including some examples and diagrams to support understanding

Clear, concise explanations supported by clearly labelled diagrams

Can successfully give examples and use the words in context

Mind Map and Answers to Questions Describes a variety of different

separation techniques and when and where they may be used

Lists one or two separation techniques and attempts to explain the science behind them

Lists the different separation techniques and explains the science behind them giving some examples of their uses and using some scientific terminology

Uses scientific terminology to clearly and concisely explain the science behind the techniques and their uses within the home or community

Science Inquiry Skills Planning and Conducting Plans and successfully conducts an investigation working cleanly and safely

Develops a basic plan for their investigation including some details around working safely

Develops a plan for their investigation which includes all relevant details Works safely and responsibly and attempts to maintain a clean work space and uses equipment appropriately

Develops a well thought out, detailed plan for the investigation including all relevant information Works safely, responsibly and with care and accuracy

Evaluating Suggests improvements to their investigation methods

Provides basic responses to the evaluation questions. More detail is needed to provide a clearer understanding

Suggests improvements to their investigative process and gives appropriate reasons to support their thinking

Gives detailed responses that clearly demonstrate a reflective process. Suggests realistic ideas for improvements and offers reasons for them

Communicating Explains the separation process using a flow chart

Has the basics needed for a flow chart but lacks the detail needed to make it clear and easy to follow

The flow chart contains relevant information and makes good use of scientific terminology. The information is sequenced and easy to follow

Detailed, easy to follow flow chart which is well labelled and clearly shows the links between the processes involved. Uses scientific terminology where appropriate

Separating the Mess

Explains the separation process using a procedural text

A written procedure is attempted but is not always clear and easy to follow. More detail is needed.

Procedure makes sense and uses appropriate conventions for procedural writing

Presents a detailed procedure which clearly follows procedural writing conventions

Application – Science as a Human Endeavour Gives examples of separation techniques used in people’s work and in industry

Is able to give an example of a separation technique that is used in people’s work and industry

Is able to give several examples of separation techniques that are used in people’s lives and in industry

Is able to give numerous examples of where separation techniques are used in people’s lives and in industry

Industry Investigation / Oral presentation Answers to Questions

Explains how science and technology have contributes to finding solutions to problems

Attempts to describe a situation where separation techniques have helped solve a problem

Explains a situation where science has helped solve a problem

Clearly explains the links between science and problem solving by giving an in depth example of where the science of separation has helped solve a problem. Is able to look at the pros and cons of the situation

Resource sheet 18

Chemical Science Equipment List

Measuring cylinders / beakers or plastic cups

Salt

Bicarb soda

Icing sugar

Citric acid

Sand

Sugar

Talcum powder

Small polystyrene balls

Iron filings

Marbles

Rice

Water

Materials to use for filtering – coffee filter paper, paper towel, chux cloths, muslin, etc

Materials for decanting – beakers, plastic cups, glass jars, measuring cylinders etc

Different sized sieves

cks etc As well as a variety of materials that can be easily separated by

eferences

ds.com/files/matter_solution.html

Tweezers and chopstithis technique e.g. buttons, different coloured beads etc

Variety of magnets – magnetic and non magnetic objects to be separated

Mixture containing – sand, iron filings, rice, salt and marbles

Polycarbonate vials

R

ttp://www.chem4kih

hniques-1733995 http://www.slideshare.net/missingisland/separation-tec

.shtml http://www.bbc.co.uk/schools/scienceclips/ages/10_11/rev_irrev_changes http://www.bbc.co.uk/schools/ks2bitesize/science/materials/ http://www.qld.waterwatch.org.au/resources/storyofariver.html

ions-solubility-d_1282.html http://www.engineeringtoolbox.com/mixtures-solutions-suspens http://www.ausetute.com.au/


http://www.chem4kids.com/files/matter_solution.html

http://www.slideshare.net/missingisland/separation-techniques-1733995

http://www.bbc.co.uk/schools/scienceclips/ages/10_11/rev_irrev_changes.shtml

http://www.bbc.co.uk/schools/ks2bitesize/science/materials/

http://www.qld.waterwatch.org.au/resources/storyofariver.html

http://www.engineeringtoolbox.com/mixtures-solutions-suspensions-solubility-d_1282.html

chemical science – year 7 -...

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