teacher notes energy (std)

My Pals are Here! Science Primary 5&6 Teachers Notes on Activity Books Energy

Theme: Energy

Chapter 1 Energy in food

Activity 1.1 Energy flow

Approximate time frame: 0.5 period

Suggested venue: Classroom

Please take note of the following:

Pg 3 For Procedure 3, the leaves can be cut using a pair of scissors instead of plucking them.

Concepts

We rely on the energy stored in food to keep us alive and to do work.

All organisms need energy to carry out life processes, such as movement, respiration and reproduction.

The Sun is the Earths main source of energy.

Specific objectives

Pupils should be able to:

state that animals depend directly or indirectly on plants for food

describe the transfer of energy along energy flow diagrams from producers to consumers

Process skills

Skill/processMeaningHow is it applied in this activity?

CommunicatingTo understand and be able to inform others of information that is presented in different forms words, diagrams, pictures, tables, graphs etc.

By using energy flow diagrams to describe the transfer of energy from one organism to another

AnalysingTo consider carefully and in detail objects, ideas, principles or series of actions in order to determine the patterns and relationships

By analysing energy flow diagrams and inferring the source of energy for all animals

Teaching suggestion

Teaching strategyExplanationTeaching suggestion

QuestioningCycles of questions-answers-questionsAsk the pupils where they get their energy from and lead them to infer that the Sun is our main source of energy.

Theme: Energy


Activity 1.2 Source of energy

Approximate time frame: 2 periods

Suggested venue: Science laboratory

Background information

Information on the experiment to test for the presence of starch in leaves

The leaves are boiled to kill the leaf cells so as to stop the process of photosynthesis.

The alcohol helps to remove chlorophyll from the leaves.

The hot water helps to soften the decolourised leaves.

Concepts

Plants are able to convert light energy from the Sun into chemical potential energy during photosynthesis.

Chlorophyll is a green pigment found in leaves that traps light energy from the Sun.

Specific objective


state that photosynthesis is the process whereby green plants manufacture food using water and carbon dioxide in the presence of chlorophyll and sunlight

Process skills


ObservingTo use the senses and/or instruments to notice the surroundings, in order to learn or understand the characteristics, properties, similarities, differences and changes of objects or events

By observing the colour change when iodine is added to the leaves

ComparingTo identify the similarities or differences between objects, ideas, principles or series of actionsBy comparing the results of the iodine test on the two leaves that have been subjected to different treatments prior to the experiment

Using apparatus and equipmentTo know how to use, which to choose and how to handle apparatus and equipment correctly for different purposes By using the pair of forceps to transfer the two leaves from one apparatus to another without tearing them

By setting up the apparatus needed for heating to be carried out

PredictingTo determine whether an outcome will happen on the basis of observations, experiences or scientific reasons

By predicting whether starch will be present in the leaf that has not been exposed to sunlight for two days prior to the experiment

Material list

MaterialQuantityRemarks

Per classPer groupPer pupil

Potted plant

Paperclip

Black paper

Beaker

Wire gauze

Tripod stand

Bunsen burner

Boiling tube

Scissors

Forceps

Alcohol

Petri dish

Iodine solution

Dropper

two leaves from the plant

4

two pieces

1

1

1

1

2

a pair

a pair

a bottle

1

a bottle

1This can be individual work if it is going to be used for assessment. Alternatively, the teacher can group the pupils into groups of four.

Safety pointers

Make sure that the beaker of hot water is only half-filled with water so that it would be easier to remove the leaves from the beaker of hot water.

Let the hot water cool before removing the boiling tubes from the beaker.

Do not use a pair of forceps to remove the leaves from the boiling tubes. Drain the alcohol in the sink instead and let the leaves slide out from each boiling tube.

Handle the leaves gently after removing them from the hot water as they are quite soft and tear easily.

Handle the iodine solution carefully as it can stain the uniform.

Keep the alcohol away from flames.

Do not light the Bunsen burner in step 5 of part E with the alcohol-filled boiling tubes in the beaker.

Teaching suggestions


QuestioningCycles of questions-answers-questionsAsk the pupils to suggest the purpose of carrying out each step prior to the iodine test.

SAILInstruction and assessmentA rubric can be used to assess each pupils performance during the experiment.

Rubric

For assessing the pupils performance during the experiment

Skill(s): Performing and Observing

Beginning

1

Developing

2Accomplished

3Score

Demonstrating experimental techniques and skillsMeets at least one but not all the criteria in level 3Meets at least two but not all the criteria in level 3 Cuts off the tip of leaf B that is not covered by black paper

Ensures the leaves are soft and fully decolourised

Moves the leaves from one apparatus to the next without tearing them

Covers the entire surface of both leaves with iodine solution

Performs the experiment safely without assistance

Making observationsMeets at least one but not all the criteria in level 3Meets at least two but not all the criteria in level 3 *Explains that the purpose of placing the leaves in the alcohol is to decolourise the leaves

*Explains that placing the leaves back into hot water after they have been decolourised is to soften the leaves

Gives an accurate description of the individual leaves stained in different colours (i.e. which leaf appears blue-black and which appears brown) after the iodine test

Skill(s): Analysing

Beginning

1

Developing

2Accomplished

3Score

Drawing conclusionsMeets at least one but not all the criteria in level 3Meets at least two but not all the criteria in level 3 Deduces from the results that leaf A contains starch but leaf B does not

Deduces from the results that plants need sunlight/light to make food

**Identifies at least one key source of experimental error and explains how it affects the accuracy of the results (e.g. failing to cut the tip off leaf B would result in confusion, failing to fully decolourise the leaves would affect the iodine test)

Total

* Note: The teacher can assess the pupil on this criterion through verbal questioning.

** Note: The teacher can assess the pupil on this criterion through verbal questioning or including an additional question in the Activity Book for the pupil to answer. The question can be phrased as, Explain how one experimental error can affect the accuracy of the results.

Theme: Energy


Activity 1.3 Experiments on photosynthesis

Approximate time frame: 1 period



Pg 8 For question 4 (b) answer, the slash is missing in the further/closer the lamp is from/to the hydrilla.

Concepts

Stomata are tiny pores found mainly on the underside of the leaf, allowing gases (carbon dioxide and oxygen) to move in and out of the leaf.

Carbon dioxide is taken in by a plant through the stomata during photosynthesis.

Water and carbon dioxide are changed into simple sugars during photosynthesis with oxygen being produced as the waste product.

Specific objectives


write a word equation for photosynthesis

state that an increase in the intensity of light would increase the rate of photosynthesis

Process skills



Part B: Rate of photosynthesis

By correctly presenting the graph with a given set of values

InferringTo give explanations to observations of objects or eventsPart A: Carbon dioxide for photosynthesis

By concluding that carbon dioxide is needed for photosynthesis from the results of the iodine test on the two leaves from set-ups A and B


By inferring that the volume of the air space in the inverted test tube (caused by the released bubbles) is an indication of the rate of photosynthesis

AnalysingTo consider carefully and in detail objects, ideas, principles or series of actions in order to determine the patterns and relationshipsPart B: Rate of photosynthesis

By analysing the set-up and concluding that the light intensity can be changed by adjusting the distance between the hydrilla and the lamp

By using the graph to state the relationship between the number of bubbles produced and the light intensity

PredictingTo determine whether an outcome will happen on the basis of observations, experiences or scientific reasons


By predicting how light intensity affects the rate of photosynthesis



QuestioningCycles of questions-answers-questionsDiscuss the questions in the Activity Book for part A only as part B is meant for assessment.

SAILInstruction and assessmentA rubric can be used to assess each pupils ability in the interpretation of results.

Rubric

For assessing each pupils ability in the interpretation of results

Skill(s): Analysing

Beginning

1

Developing

2Accomplished

3Score

Processing dataMeets at least one but not all the criteria in level 3

Meets at least two but not all the criteria in level 3 All points on the graph are accurately plotted

A best fit line is drawn

Line is drawn using a ruler

Drawing conclusionsMeets at least one but not all the criteria in level 3Meets at least two but not all the criteria in level 3 Infers that the light intensity can be adjusted by varying the distance between the hydrilla and the lamp

Deduces from the results that the further/closer the lamp is from/to the hydrilla, the fewer/greater the number of bubbles produced per minute respectively

Deduces from the results that the fewer/greater the number of bubbles produced per minute, the slower/faster the rate of photosynthesis respectively

Total

Theme: Energy

Chapter 2 Forms and uses of energy

Activity 2.1 Away we go!



Concepts

Energy is the ability to do work.

A raised object possesses gravitational potential energy.

If there are two objects of the same mass being raised, the object that is raised higher possesses greater gravitational potential energy.

Specific objectives


state that a raised object possesses gravitational potential energy

state that the higher an object is raised, the greater the amount of gravitational potential energy it possesses

Process skills



By observing the relationship between the increase in the height of the ramp and the distance moved by the car on the ground

Using apparatus and equipmentTo know how to use, which to choose and how to handle apparatus and equipment correctly for different purposes

By changing the height of the ramp after obtaining each set of values

InferringTo give explanations to observations of objects or eventsBy inferring that an increase in the height of the ramp results in an increase in the distance moved by the car along the ground

Material list



Plastic conduit (4 cm wide, 60 cm long)

Wooden block (3 cm thick)

Measuring tape

Toy car 1

4

1

1Each group can have four pupils.

Each pupil can take turns to take the measurement so that the teacher can effectively asses each pupil.



QuestioningCycles of questions-answers-questionsDiscuss the questions in the Activity Book with the pupils.

SAILInstruction and assessmentA rubric can be used to assess each pupils performance during cooperative-learning.

Rubric

For assessing the pupils performance during cooperative-learning

Skill(s): Collaborative work skills

CriteriaBeginning

1

Developing

2Accomplished

3Score

ContributionsParticipates only when prompted Participates with occasional prompting

A satisfactory group member who does what is required Participates without prompting

Routinely provides useful ideas

A definite leader who contributes a lot of effort

Quality of workProvides work that usually needs to be checked or redone by other group members to ensure quality (e.g. while taking the measurement, he/she does not ensure that the measurement is taken properly and makes more than two mistakes)

Provides work that occasionally needs to be checked or redone by other group members to ensure quality (e.g. while taking the measurement, he/she only makes one or two mistakes)Provides work of the highest quality (Note: No mistake was made while taking the measurement.)

Time management Rarely gets things done

The group has to change work responsibilities because of this pupil

Usually task focused but gets distracted occasionally and needs to be reminded to stay on taskIs consistently focused on the task and uses time well throughout the experiment to ensure that things get done on time

Problem-solving Does not try to solve problems or help others solve problems

Lets others do the workDoes not suggest or refine solutions, but is willing to try out solutions suggested by othersActively looks for and suggests solutions to problems (e.g. if the surface of the ground is too rough for the car to move, he/she may suggest covering the ground with books as book covers are smooth)

Working with others Rarely listens to, shares with or supports the efforts of others

Is not a good team playerOften listens to, shares with and supports the efforts of others, but stays aloof and indifferent when there is a conflict among the group members Almost always listens to, shares with and supports the efforts of others

Tries to keep the group members working well together

Total

Extension (page 11)



By analysing the relationship between the height of the ramp and the distance moved by the car on the ground

Theme: Energy


Activity 2.2 Falling can


Suggested venue: School field

Concepts

An object that is raised higher possesses greater gravitational potential energy.

The more gravitational potential energy an object has, the greater the depression it can make when it is allowed to fall onto a tray of flour.

Specific objectives


state that the higher an object is raised, the greater the amount of gravitational potential energy it possesses

state that the more gravitational potential energy an object has, the greater the depression it can make when it is allowed to fall onto a tray of flour

Process skills



By observing the relationship between the increase in the height of the mineral water bottle and the depth of the depression it makes in the flour

Using apparatus and equipmentTo know how to use, which to choose and how to handle apparatus and equipment correctly for different purposesBy varying the height of the mineral water bottle from where it is to be dropped and using a 30 cm ruler to measure the depth of the depression made in the flour

InferringTo give explanations to observations of objects or eventsBy inferring that an increase in the height of the raised mineral water bottle results in an increase in the depth of the depression made in the flour

Material list



Filled mineral water bottle

Deep tray (at least 20 cm deep) filled with flour

30 cm ruler

1

1


Each pupil can take turns to take the measurement.

Safety pointer

Make sure that every group member has cleared away from the tray of flour before the mineral water bottle is dropped.



QuestioningCycles of questions-answers-questionsDiscuss the questions in the Activity Book with the pupils.


Rubric



CriteriaBeginning

1

Developing

2Accomplished

3Score










*Problem-solving Does not try to solve problems or help others solve problems

Lets others do the workDoes not suggest or refine solutions, but is willing to try out solutions suggested by othersActively looks for and suggests solutions to problems (e.g. suggests using a strand of string to assist in taking the measurement of the depth of the depression to improve the accuracy of the readings)




Total

* Note: The teacher can pose the problem verbally and get the pupils in the group to write down the solution at a specific location in the Activity Book.

Theme: Energy


Activity 2.3 Super launcher



Concepts

Elastic potential energy is present in a wound-up toy, stretched rubber band, compressed or stretched spring.

Energy can be converted from one form to another.

Specific objectives


describe the changes in the forms of energy when a paper ball is launched by a stretched plastic spoon

infer that with an increase in the amount of elastic potential energy in the stretched plastic spoon, the distance covered by the paper ball launched by the plastic spoon will be greater

Process skills



By observing the change in the distance covered by the paper ball in the three attempts

InferringTo give explanations to observations of objects or eventsBy interpreting that if the plastic spoon is stretched further back, it will store more elastic potential energy, allowing more energy to be transferred to the paper ball and causing it to fly further

Using apparatus and equipmentTo know how to use, which to choose and how to handle apparatus and equipment correctly for different purposesBy launching the paper ball safely and ensuring that the plastic spoon is stretched backwards at different angles in the three attempts

Material list



Long plastic spoon

Small piece of paper rolled into a ball

Chalk

Measuring tape 1

1

1

1The teacher can get the pupils to work in a pair and rotate between themselves when carrying out the steps. This is to facilitate the teacher in assessing each pupil using the rubric.

Safety pointer

Make sure that nobody is standing in front of you when the paper ball is about to be launched.



QuestioningCycles of questions-answers-questionsAsk the pupils to predict the relationship between the degree at which the plastic spoon is stretched backwards and the distance covered by the paper ball.


Rubric



Beginning

1

Developing

2Accomplished

3Score

Demonstrating experimental techniques and skillsMeets at least one but not all the criteria in level 3Meets at least two but not all the criteria in level 3 Uses the thumb to hold the plastic spoon firmly against the edge of the desk (Note: If the plastic spoon slips before the paper ball is launched, the pupil is not holding the plastic spoon firm enough. Only penalise the pupil when the plastic spoon slips twice.)

Uses a chalk to mark the spot where the paper ball first lands on the table (The paper ball might roll off after touching the table and the pupil should not take the distance covered by the paper ball after it rolls off.)

Ensures that the plastic spoon is stretched backwards at different angles in the three attempts

Making observations and taking measurementsMeets at least one but not all the criteria in level 3Meets at least two but not all the criteria in level 3 Measure the distance between the plastic spoon and the paper ball accurately

Records three readings for the three attempts

All the results follow the same trend as the teachers results

Skill(s): Analysing

Beginning

1

Developing

2Accomplished

3Score

Drawing conclusionsMeets at least one but not all the criteria in level 3Meets at least two but not all the criteria in level 3 Deduces from the results that the paper ball will travel further when the plastic spoon is stretched further backwards

Infers from the results that stretching the plastic spoon further back increases the amount of elastic potential energy stored in it

Explains that when the stretched plastic spoon is released, the elastic potential energy is transferred to the paper ball and changes into kinetic energy when the paper ball flies forward

Total

Extension (page 15)


QuestioningCycles of questions-answers-questionsDiscuss the energy conversions in a pinball machine.

Theme: Energy


Activity 2.4 Stretch, twist and go!



Concepts


Potential energy is a form of energy that can be stored.

Specific objective


work in a team to carry out an experiment

Process skills


PredictingTo determine whether an outcome will happen on the basis of observations, experiences or scientific reasonsBy predicting how an increase in the number of twists made to the rubber band on the toy can affect the distance covered by it

Using apparatus and equipmentTo know how to use, which to choose and how to handle apparatus and equipment correctly for different purposesBy making the toy using the materials provided and changing the number of twists made to the rubber band on the toy to obtain different sets of readings


By observing the relationship between the number of twists made to the rubber band on the toy and the distance covered by it

InferringTo give explanations to observations of objects or eventsBy inferring that the greater the number of twists made, the further the toy will travel

Material list



Empty thread spool (at least 2 cm in diameter)

Rubber band

Stick (must be longer than the diameter of the thread spool)

1

1


Each pupil can take turns to take the measurement.


Teaching strategy

ExplanationTeaching suggestion(s)

InvestigatingTo carry out a scientific inquiry in order to achieve a certain learning objective

Ask the pupils to predict how the increase in the number of twists made to the rubber band will affect the distance travelled by the toy.

Get the pupils to carry out the experiment to test their prediction.

Get the pupils to summarise their findings using a table. A sample of what their table may look like:

No. of twists

Distance covered in the 1st attempt (cm)

Distance covered in the 2nd attempt (cm)

Distance covered in the 3rd attempt (cm)

Average (cm)

10

20

30


Rubric



CriteriaBeginning

1

Developing

2Accomplished

3Score










*Problem-solving Does not try to solve problems or help others solve problems

Lets others do the workDoes not suggest or refine solutions, but is willing to try out solutions suggested by othersActively looks for and suggests solutions to problems (e.g. if the surface of the ground is too rough for the toy to move, he/she may suggest covering the ground with books as book covers are smooth)




Total

* Note: The teacher can pose the problem verbally and get the pupils in the group to write down the solution at a specific location in the Activity Book.

Theme: Energy


Activity 2.5 Get energised!



Concepts


Energy is needed for an object to do work.

There are three different forms of potential energy, namely chemical, elastic and gravitational potential energy.

Specific objectives


describe the steps for carrying out each activity

state the changes in the forms of energy for each activity conducted

Process skills



By observing the outcomes of each individual activity


By recording the observations in a table


By using the different apparatus provided to carry out the different activities

Generating possibilitiesTo come up with other potential possibilities besides the common oneBy generating different methods of producing different forms of energy for activities D and E

Material list



Activity A

Light bulb

Connecting wire

Switch

Battery

Battery holder

Activity B

Rock

Activity C

Toy windmill

Activity D

Glass bottle half-filled with water

Metal spoon

Activity E

Plastic ruler (30 cm long)

Plasticine (a small lump)

Roll of tape

1

3

1

1

1

two pieces

1

1

1

1

1

1The teacher can prepare two sets of apparatus for each activity.

It will be individual work but only 20 pupils can be assessed each time to reduce confusion. The other half of the class can be kept in the classroom to do written work.

Laboratory assistant(s) can be roped in to assist the teacher.

Safety pointers

Handle the rock with care as there might be sharp edges.

Make sure that the bottle is not hit too hard as it may cause the bottle to topple over.

Make sure that nobody is standing next to you when you are catapulting the plasticine.

Teaching suggestion


SAILInstruction and assessmentA rubric can be used to assess each pupils ability in the interpretation of results.

Rubric

For assessing each pupils ability in the interpretation of results

Skill(s): Analysing

Beginning

1

Developing

2Accomplished

3Score

Processing dataMeets at least one but not all the criteria in level 3Meets at least two but not all the criteria in level 3 Describes the steps clearly for all the activities (assess what the pupil has written in the column What I did in table A)

Makes clear observations for all the activities (assess what the pupil has written in the column What I observed in table A)

No spelling mistakes made in table A

Drawing conclusionsMeets at least one but not all the criteria in level 3Meets at least two but not all the criteria in level 3 Deduces correctly the form(s) of energy produced for all the activities

Deduces that one form of energy can be converted to many other forms (Note: This criterion can be assessed using question 1 from the Conclusions section.)

Deduces from the activities that energy is always being converted from one form to another (Note: This criterion can be assessed using question 3 from the Conclusions section.)

Total

Extension (page 19)

Process skill(s)DescriptionComments

Communicating, analysingPupils are to study a line graph and draw a conclusion based on the graph given.Ask pupils what are the conclusions that can be drawn from the graph. (Answer: There are continuous conversions of energy as Zoe swings from one end to another. She possesses the greatest gravitational potential energy but the least kinetic energy at the highest point. She also possesses the greatest kinetic energy but the least gravitational energy at the lowest point.)

Theme: Energy


Activity 2.6 Energy conversions




Pg 21 For Extension question, the arrow is missing after _____ energy (in moving steam).

Concepts

There are different forms of energy.

Energy can be stored for later use, e.g. we can store chemical potential energy in batteries.

We change energy to other form(s) that we can use, e.g. we use a fan to change electrical energy to kinetic energy.

Specific objectives


state the forms of energy in each example of energy conversion

list the similarities and the differences between a fossil fuel power station and a hydroelectric power station

Process skills



By using the different examples to describe how energy is converted from one form to another


By analysing the consequences of removing electricity, which is a widely used form of energy, and the inconvenience it would bring to our lives if it was to be removed

Teaching suggestion


QuestioningCycles of questions-answers-questionsAsk the pupils to suggest the consequences if electricity is to be removed from their lives.

Extension (page 21)

Teaching strategyExplanationTeaching suggestions

QuestioningCycles of questions-answers-questions Discuss the conversion of the different forms of energy in a fossil fuel power station.

Get the pupils to compare and contrast the similarities and differences between a fossil fuel power station and a hydroelectric power station.

Theme: Energy


Activity 2.7 Energy transformations

Approximate time frame: 2 periods



Pg 23 For Materials, the batteries can be used alone if the battery holders are not available.

Pg 25 For the diagram, the width of the bands can be increased to improve the swirling effect of the spiral.

Concepts


A candle and a battery possess chemical potential energy.

Specific objective


work in a team to carry out an experiment

Process skills



By observing the outcomes of the two experiments


By tying the paper spiral properly to the retort stand and ensuring that it spins after the candle is lit up


By analysing the two set-ups and describing how energy conversion takes place

PredictingTo determine whether an outcome will happen on the basis of observations, experiences or scientific reasonsBy predicting the outcomes of the two experiments (i.e. what will happen to the paper spiral and the nichrome wire respectively during the experiments)

Material list



Experiment A

Cardboard (13 cm x 13 cm)

String (10 cm long)

Retort stand

Candle

Matches

Experiment B

Battery (1.5 V)

Battery holder (if available) Switch

Insulated wire

Nichrome wire (5 cm)

Metal pin

Eraser

Candle

a sheet

a strand

1

1

a box

4

4

1

3

1

2

1

1Each group can have two pupils.

Safety pointers

Experiment A

Make sure that the paper spiral is not too near the candle before lighting it up.

Make sure that the paper spiral is tied properly to the retort stand.

Handle the burning candle with care.

Experiment B Do not touch the nichrome wire during the experiment as it would be hot.

Do not touch the melting wax of the candle.



QuestioningCycles of questions-answers-questionsDiscuss the questions in the Activity Book for experiment B with the pupils.

Cooperative learningAn environment in which pupils assume different roles to contribute to the completion of tasksPupils are asked to divide the workload equally between their partner and themselves.


Rubric

For assessing the pupils performance during cooperative-learning (Note: Only meant for experiment A)


CriteriaBeginning

1

Developing

2Accomplished

3Score





*Quality of workProvides work that usually needs to be checked or redone by the partner to ensure quality (Note: Makes two of the following mistakes:

Fails to paste the page onto the cardboard before making the hole

Fails to follow the circular line while cutting the paper spiral

Fails to tie one end of the string properly to the retort stand and the other end properly to the paper spiral

Fails to stick the candle firmly to the retort stand)

Provides work that occasionally needs to be checked or redone by the partner to ensure quality (Note: Makes one of the mistakes in level 1.)Provides work of the highest quality (Note: Makes none of the mistakes in level 1.)


The partner has to change work responsibilities because of this pupil


Problem-solving Does not try to solve problems or help the partner solve problems

Lets the partner do the workDoes not suggest or refine solutions, but is willing to try out solutions suggested by the partnerActively looks for and suggests solutions to problems (e.g. if the candle is touching the paper spiral, he/she may suggest shortening it)

Working with othersRarely listens to, shares with or supports the efforts of the partnerOften listens to, shares with and supports the efforts of the partnerAlmost always listens to, shares with and supports the efforts of the partner

Total

* Note: The teacher needs to make sure that each member covers two of the tasks mentioned in level 1 so that each pupil in a pair can effectively be assessed for that criterion.

Extension (pg 24)


QuestioningCycles of questions-answers-questionsDiscuss the energy conversions that occur in a floating paper lantern.

Theme: Energy

Chapter 3 Sources of energy

Activity 3.1 Water wheel

Approximate time frame: 1.5 periods


Concept

Sources of energy can be classified as renewable or non-renewable.

Specific objectives


write down the energy conversions in a hydroelectric power station

state the advantages and disadvantages of having a hydroelectric power station over a fossil fuel power station

Process skills



By observing the change in the speed of the spinning water wheel when the speed of the running water is increased

InferringTo give explanations to observations of objects or eventsBy interpreting the energy conversions that happen in a hydroelectric power station


By using the materials provided to make a water wheel

Material list



Paper cup

Scissors

Pencil

Adhesive gum

1

a pair

1

a packet

Teaching suggestion



Rubric



Beginning 1

Developing

2Accomplished

3Score

Demonstrating experimental techniques and skillsMeets at least one but not all the criteria in level 3Meets at least two but not all the criteria in level 3 Cuts four triangular slits down the sides of the cup towards the base properly

Presses the remaining pieces down properly

Makes an angled bent properly at one corner for each blade

Uses adhesive gum to secure the end that is poked through by a pencil properly

Making observationsMeets at least one but not all the criteria in level 3Meets at least two but not all the criteria in level 3 Describes clearly what is seen when the water wheel is held under running water

Describes clearly that when there is a greater flow of water, the wheel will turn faster

Gives an accurate description of the energy conversions for the moving water wheel

Skill(s): Analysing

Beginning 1

Developing

2Accomplished

3Score

Drawing conclusionsMeets at least one but not all the criteria in level 3Meets at least two but not all the criteria in level 3 Deduces from the results that when there is a greater flow of water, there is more gravitational potential energy and the running water passes more kinetic energy to the water wheel, causing it to turn faster

States a reason why running water is not used to generate electricity in Singapore (Note: This criterion can be assessed using question 1(b) from the Extension section.)

*Identifies at least one key source of experimental error and explains how it affects the accuracy of the results (e.g. failing to cut the slits properly would prevent the wheel from turning smoothly, failing to secure the end properly would cause the wheel to slide off the pencil)

Total

* Note: The teacher can assess the pupil on this criterion through verbal questioning or including an additional question in the Activity Book for the pupil to answer. The question can be phrased as, Explain how one experimental error can affect the accuracy of the results.Extension (page 29)Teaching strategyExplanationTeaching suggestion

QuestioningCycles of questions-answers-questionsDiscuss the questions in the Activity Book with the pupils. (Note: Omit question 1(b) as it has been used for assessing the pupils in the rubric.)

Theme: Energy

Chapter 3 Sources of energy

Activity 3.2 Windmill



Concept

Renewable sources of energy such as running water, wind and waves can be used to generate electricity.

Specific objectives


write down the energy conversions in a wind power station

state the advantages and disadvantages of having a wind power station over a fossil fuel power station

Process skills



By observing the change in the speed of the turning windmill when the speed of the wind is changed

InferringTo give explanations to observations of objects or eventsBy interpreting the energy conversions that happen in a wind power station


By using the materials to make a windmill

Material list



Square paper (10 cm by 10 cm)

Scissors

Straw (15 cm long)

Adhesive gum

Wire (longer than straw)

Eraser

Small fan a piece

a pair

1

a packet

a piece

1

1 (to be shared by four pupils in a bench)The teacher can place a fan at each bench and get the pupils to share among themselves. The speed of the fan can be changed to see what effect it has on their windmills.

Teaching suggestion



Rubric



Beginning 1

Developing

2Accomplished

3Score

Demonstrating experimental techniques and skillsMeets at least one but not all the criteria in level 3Meets at least two but not all the criteria in level 3 Draws the diagonal lines on the paper using a ruler

Makes five holes on the paper at the appropriate locations, each with a diameter that is slightly greater than that of the straw

Uses the adhesive gum to secure the end properly

Threads the wire through the straw properly so that the windmill can turn freely

Making observationsMeets at least one but not all the criteria in level 3Meets at least two but not all the criteria in level 3 Describes clearly what is seen when the windmill is facing moving air

Describes clearly that when there is an increase in the speed of the wind, the windmill will turn faster

Gives an accurate description of the energy conversions for the turning windmill

Skill(s): Analysing

Beginning 1

Developing

2Accomplished

3Score

Drawing conclusionsMeets at least one but not all the criteria in level 3Meets at least two but not all the criteria in level 3 Deduces from the results that when there is an increase in the wind speed, the stronger wind passes more kinetic energy to the windmill, causing it to turn faster

States a reason why wind energy is not used to generate electricity in Singapore (Note: This criterion can be assessed using question 1(c) from the Extension section.)

*Identifies at least one key source of experimental error and explains how it affects the accuracy of the results (e.g. failing to thread the wire through the straw properly would prevent it from turning smoothly, failing to secure the end properly would cause the windmill to split open)

Total

* Note: The teacher can assess the pupil on this criterion through verbal questioning or including an additional question in the Activity Book for the pupil to answer. The question can be phrased as, Explain how one experimental error can affect the accuracy of the results.

Extension (page 32)


QuestioningCycles of questions-answers-questionsDiscuss the questions in the Activity Book with the pupils. (Note: Omit question 1(c) as it has been used for assessing the pupils in the rubric.)

Theme: Energy

Revision Exercise Energy



Section A: Multiple-choice questions

QuestionContent domainMain topic(s)Process skill(s)

How is it applied in this question?

1Life ScienceChapter 1 Energy in foodClassifyingBy determining whether each given substance is a raw material or an end product of photosynthesis

2Life ScienceChapter 1 Energy in foodEvaluatingBy evaluating which of the given substances should be used to complete the statement

3Physical ScienceChapter 3 Sources of energy

ClassifyingBy identifying only the sources of energy from a given list

4Physical ScienceChapter 3 Sources of energyClassifyingBy identifying only the type of power station that uses chemical energy to produce electricity from a given list

5Physical ScienceChapter 2 Forms and uses of energy

InferringBy inferring the energy conversions in lighted fireworks

Section B: Structured questions

QuestionContent domainMain topic(s)Process skill(s)How is it applied in this question?

6Life ScienceChapter 1 Energy in food Inferring

Analysing By identifying the region that contains starch from the results of the iodine test

By deducing that in an iodine test, iodine will remained brown in regions where chlorophyll is not present

7Life ScienceChapter 1 Energy in food Analysing

Inferring By deducing that energy from the caterpillar is passed to the bird when the former is being consumed by the latter

By inferring that energy is being transferred from one organism to the next in the flowchart

8Physical ScienceChapter 2 Forms and uses of energyInferringBy inferring the energy conversions for a ball that is thrown upwards and later falls downwards

9Physical Science Chapter 3 Sources of energy

Chapter 2 Forms and uses of energy Analysing

Inferring By analysing the design of the maglev wind turbine and deducing how energy loss is greatly reduced using this type of wind turbine

By inferring the energy conversions for the power station that uses the maglev wind turbine

10Physical Science Chapter 1 Energy in food

Chapter 2 Forms and uses of energy Analysing

Inferring By deducing the source of energy for the horse and the forms of energy it exhibits as it runs

By inferring the energy conversions for the horse that jumps over a pole and lands onto the ground

11Physical ScienceChapter 3 Sources of energyAnalysingBy deducing one advantage and one disadvantage of using solar cells

PAGE 22 2009 Marshall Cavendish International (Singapore) Pte Ltd

teacher notes energy (std)

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