Miami-Dade County Public Schools

Office of Academics and Transformation

Required

ESSENTIAL

Laboratory Activities

For the Middle School

M/J Comprehensive Science 3

REVISED May 2013 THE SCHOOL BOARD OF MIAMI-DADE COUNTY, FLORIDA

Ms. Perla Tabares Hantman, Chair

Dr. Martin Karp, Vice Chair

Dr. Dorothy Bendross-Mindingall

Ms. Susie V. Castillo

Mr. Carlos L. Curbelo

Dr. Lawrence S. Feldman

Dr. Wilbert “Tee” Holloway

Dr. Marta Pérez

Ms. Raquel A. Regalado

Mr. Jude Bruno

Student Advisor

Mr. Alberto M. Carvalho

Superintendent of Schools

Ms. Milagros R. Fornell

Chief Academic Officer

Office of Academics and Transformation

Ms. Marie L. Izquierdo

Assistant Superintendent

Division of Academics, Accountability & School Improvement

Office of Academics and Transformation

Mr. Cristian Carranza

Administrative Director

Office of Academics and Transformation

Dr. Ava D. Rosales

Executive Director

Department of Mathematics and Science

Office of Academics and Transformation

Table of Contents

Introduction4

Annually Assessed Benchmarks5

Materials List8

Lab Roles10

Safety Information and Contract11

Pre-Lab Safety Worksheet and Approval Form12

Parts of a Lab Report13

Experimental Design Diagram17

Claim Evidence Reasoning19

Engineering Design Process20

Lab Activities:

Physical Properties of Matter Inquiry Lab………………………………………….………..21

Density of Rocks with Differentiated Lab24

Density of Rocks (Revised by University of Miami Science Made Sensible Fellows)32

Mass, Volume, Density with Differentiated Lab (Comprehensive Science 3 Advanced)38

Precipitating Bubbles with Differentiated Lab44

Greenhouse Gases in a Bottle with Differentiated Lab56

Conservation of Mass…………………………………………………………………………...60

Carbon Cycle Game65

Modeling Recycling of Matter and Energy Differentiated Lab78

The Martian Sun-Times79

Properties of Objects in the Solar System Differentiated Lab 85

Imaginary Alien Life-forms with Differentiated Lab (Adaptations and Punnett Square)86

Planetary Exploration and Extreme Life Forms with Differentiated Lab103

Revised by University of Miami Science Made Sensible Fellows

Differentiated Lab Visualizing Our Solar System Scale Models109

What Causes the Seasons?.........................................................................................................110

Introduction

The purpose of this packet is to provide the M/J Comprehensive Science 3 and Grade 8 teachers with a list of minimum basic laboratories and hands-on activities that students should experience in class. Each activity is aligned with the Next Generation Sunshine State Standards (NGSSS). Emphasis has been placed on those hands-on activities that are aligned to the Annually Assessed Benchmarks, which are assessed in the Florida Comprehensive Assessment Test 2.0 (FCAT 2.0), administered in grade eight (8).

In most cases, the activities were designed as simple as possible without the use of advanced technological equipment to make it possible for all teachers to use these activities. All activities and supplements (i.e., Parts of a Lab Report) can be modified, if necessary, to fit the needs of an individual class and/or student ability.

This document is intended to be used by science departments in M-DCPS so that all science teachers can work together, plan together, and rotate lab materials among classrooms. Through this practice, all students and teachers will have the same opportunities to participate in these experiences and promote discourse among learners which are the building blocks of authentic learning communities.

Acknowledgement:

M-DCPS Department of Mathematics and Science would like to acknowledge the efforts of the teachers who worked arduously and diligently on the preparation of this document.

Annually Assessed Benchmarks

Next Generation Sunshine State Standard (NGSSS)

SC.8.N.1.1 Define a problem from the eighth grade curriculum using appropriate reference materials to support scientific understanding, plan and carry out scientific investigations of various types, such as systematic observations or experiments, identify variables, collect and organize data, interpret data in charts, tables, and graphics, analyze information, make predictions, and defend conclusions. (Also assesses SC.6.N.1.1, SC.6.N.1.3, SC.7.N.1.1, SC.7.N.1.3, SC.7.N.1.4, SC.8.N.1.3, and SC.8.N.1.4.) (Cognitive Complexity Level 3: Strategic Thinking and Complex Reasoning)

SC.7.N.1.2 Differentiate replication (by others) from repetition (multiple trials). (Also assesses SC.6.N.1.2, SC.6.N.1.4, and SC.8.N.1.2.) (Cognitive Complexity Level 2: Basic Application of Skills and Concepts)

SC.7.N.1.5 Describe the methods used in the pursuit of a scientific explanation as seen in different fields of science such as biology, geology, and physics. (Also assesses SC.7.N.3.2, SC.8.N.1.5, and SC.8.E.5.10.) (Cognitive Complexity Level 2: Basic Application of Skills and Concepts)

SC.6.N.2.2 Explain that scientific knowledge is durable because it is open to change as new evidence or interpretations are encountered. (Also assesses SC.7.N.1.6, SC.7.N.1.7, SC.7.N.2.1, and SC.8.N.1.6.) (Cognitive Complexity Level 2: Basic Application of Skills and Concepts)

SC.7.N.3.1 Recognize and explain the difference between theories and laws and give several examples of scientific theories and the evidence that supports them. (Also assesses SC.6.N.3.1 and SC.8.N.3.2.) (Cognitive Complexity Level 3: Strategic Thinking and Complex Reasoning)

SC.8.E.5.3 Distinguish the hierarchical relationships between planets and other astronomical bodies relative to solar system, galaxy, and universe, including distance, size, and composition. (Also assesses SC.8.E.5.1 and SC.8.E.5.2.) (Cognitive Complexity Level 3: Strategic Thinking and Complex Reasoning)

SC.8.E.5.5 Describe and classify specific physical properties of stars: apparent magnitude (brightness), temperature (color), size, and luminosity (absolute brightness). (Also assesses SC.8.E.5.6.) (Cognitive Complexity Level 2: Basic Application of Skills and Concepts)

SC.8.E.5.7 Compare and contrast the properties of objects in the Solar System including the Sun, planets, and moons to those of Earth, such as gravitational force, distance from the Sun, speed, movement, temperature, and atmospheric conditions. (Also assesses SC.8.E.5.4 and SC.8.E.5.8.) (Cognitive Complexity Level 2: Basic Application of Skills and Concepts)

SC.8.E.5.9 Explain the impact of objects in space on each other including: 1. the Sun on the Earth including seasons and gravitational attraction 2. the Moon on the Earth, including phases, tides, and eclipses, and the relative position of each body. (Cognitive Complexity Level 3: Strategic Thinking and Complex Reasoning)

SC.7.E.6.2 Identify the patterns within the rock cycle and events (plate tectonics and mountain building). (Also assesses SC.6.E.6.1, SC.6.E.6.2, and SC.7.E.6.6.) relate them to surface events (weathering and erosion) and subsurface events (plate tectonics and mountain building). (Also assesses SC.6.E.6.1, SC.6.E.6.2, and SC.7.E.6.6.) (Cognitive Complexity Level 3: Strategic Thinking and Complex Reasoning)

SC.7.E.6.4 Explain and give examples of how physical evidence supports scientific theories that Earth has evolved over geologic time due to natural processes. (Also assesses SC.7.E.6.3.) (Cognitive Complexity Level 3: Strategic Thinking and Complex Reasoning)

SC.7.E.6.5 Explore the scientific theory of plate tectonics by describing how the movement of Earth’s crustal plates causes both slow and rapid changes in Earth’s surface, including volcanic eruptions, Earthquakes, and mountain building. (Also assesses SC.7.E.6.1 and SC.7.E.6.7.) (Cognitive Complexity Level 2: Basic Application of Skills and Concepts)

SC.6.E.7.4 Differentiate and show interactions among the geosphere, hydrosphere, cryosphere, atmosphere, and biosphere. (Also assesses SC.6.E.7.2, SC.6.E.7.3, SC.6.E.7.6, and SC.6.E.7.9.) (Cognitive Complexity: Level 3: Strategic Thinking & Complex Reasoning)

SC.6.E.7.5 Explain how energy provided by the Sun influences global patterns of atmospheric movement and the temperature differences between air, water, and land. (Also assesses SC.6.E.7.1.) (Cognitive Complexity: Level 3: Strategic Thinking & Complex Reasoning)

SC.8.P.8.4 Classify and compare substances on the basis of characteristic physical properties that can be demonstrated or measured; for example, density, thermal or electrical conductivity, solubility, magnetic properties, melting and boiling points, and know that these properties are independent of the amount of the sample. (Also assesses SC.8.P.8.3.) (Cognitive Complexity Level 2: Basic Application of Skills and Concepts)

SC.8.P.8.5 Recognize that there are a finite number of elements and that their atoms combine in a multitude of ways to produce compounds that make up all of the living and nonliving things that we encounter. (Also assesses SC.8.P.8.1, SC.8.P.8.6, SC.8.P.8.7, SC.8.P.8.8, and SC.8.P.8.9.) (Cognitive Complexity Level 1: Recall)

SC.8.P.9.2 Differentiate between physical changes and chemical changes. (Also assesses SC.8.P.9.1 and SC.8.P.9.3.) (Cognitive Complexity Level 2: Basic Application of Skills and Concepts)

SC.7.P.10.1 Illustrate that the Sun’s energy arrives as radiation with a wide range of wavelengths, including infrared, visible, and ultraviolet, and that white light is made up of a spectrum of many different colors. (Also assesses SC.8.E.5.11.) (Cognitive Complexity Level 1: Recall)

SC.7.P.10.3 Recognize that light waves, sound waves, and other waves move at different speeds in different materials. (Also assesses SC.7.P.10.2.) (Cognitive Complexity Level 1: Recall)

SC.7.P.11.2 Investigate and describe the transformation of energy from one form to another. (Also assesses SC.6.P.11.1 and SC.7.P.11.3.) (Cognitive Complexity Level 2: Basic Application of Skills and Concepts)

SC.7.P.11.4 Observe and describe that heat flows in predictable ways, moving from warmer objects to cooler ones until they reach the same temperature. (Also assesses SC.7.P.11.1.) (Cognitive Complexity Level 2: Basic Application of Skills and Concepts)

SC.6.P.13.1 Investigate and describe types of forces including contact forces and forces acting at a distance, such as electrical, magnetic, and gravitational. (Also assesses SC.6.P.13.2 and SC.8.P.8.2.) (Cognitive Complexity Level 2: Basic Application of Skills and Concepts)

SC.6.P.13.3 Investigate and describe that an unbalanced force acting on an object changes its speed, or direction of motion, or both. (Also assesses SC.6.P.12.1.) (Cognitive Complexity Level 2: Basic Application of Skills and Concepts)

SC.6.L.14.1 Describe and identify patterns in the hierarchical organization of organisms from atoms to molecules and cells to tissues to organs to organ systems to organisms. (Cognitive Complexity Level 1: Recall)

SC.6.L.14.2 Investigate and explain the components of the scientific theory of cells (cell theory): all organisms are composed of cells (single-celled or multi-cellular), all cells come from preexisting cells, and cells are the basic unit of life. (Also assesses SC.6.L.14.3.) (Cognitive Complexity Level 2: Basic Application of Skills and Concepts)

SC.6.L.14.4 Compare and contrast the structure and function of major organelles of plant and animal cells, including cell wall, cell membrane, nucleus, cytoplasm, chloroplasts, mitochondria, and vacuoles. (Cognitive Complexity Level 2: Basic Application of Skills and Concepts)

SC.6.L.14.5 Identify and investigate the general functions of the major systems of the human body (digestive, respiratory, circulatory, reproductive, excretory, immune, nervous, and musculoskeletal) and describe ways these systems interact with each other to maintain homeostasis. (Also assesses SC.6.14.6.) (Cognitive Complexity: Level 3: Strategic Thinking & Complex Reasoning)

SC.6.L.15.1 Analyze and describe how and why organisms are classified according to shared characteristics with emphasis on the Linnaean system combined with the concept of Domains. (Cognitive Complexity: Level 3: Strategic Thinking & Complex Reasoning)

SC.7.L.15.2 Explore the scientific theory of evolution by recognizing and explaining ways in which genetic variation and environmental factors contribute to evolution by natural selection and diversity of organisms. (Also assesses SC.7.L.15.1 and SC.7.L.15.3.) (Cognitive Complexity: Level 3: Strategic Thinking & Complex Reasoning)

SC.7.L.16.1 Understand and explain that every organism requires a set of instructions that specifies its traits, that this hereditary information (DNA) contains genes located in the chromosomes of each cell, and that heredity is the passage of these instructions from one generation to another. (Also assesses SC.7.L.16.2 and SC.7.L.16.3.) (Cognitive Complexity: Level 3: Strategic Thinking & Complex Reasoning)

SC.7.L.17.2 Compare and contrast the relationships among organisms such as mutualism, predation, parasitism, competition, and commensalism. (Also assesses SC.7.L.17.1 and SC.7.L.17.3.) (Cognitive Complexity Level 2: Basic Application of Skills and Concepts)

SC.8.L.18.4 Cite evidence that living systems follow the Laws of Conservation of Mass and Energy. (Also assesses SC.8.L.18.1, SC.8.L.18.2, and SC.8.L.18.3.) (Cognitive Complexity: Level 3: Strategic Thinking & Complex Reasoning)

Materials List

Each list corresponds to the amount of materials needed per station (whether one student or a group of students uses the station). Lab Aprons and goggles should be assigned to each student on all labs requiring mixtures of chemicals.

Physical Properties of Matter

•Sugar•Wood chips•Iron (fillings or staples)•Sand•Water•Magnet

· Coffee filter

· Graduated Cylinder

· Triple Beam Balance

· Thermometer

· Beaker

· Hot Plate

Density of Rocks

·

114

EL8_2013

· Graduated cylinder

· 250 mL beaker

· medicine dropper

· food coloring ( not essential but helpful)

· 100 mL graduated cylinder

· Eye dropper

· Calculator

· Electronic balance or triple-beam balance

· 5 different type of rocks

· Tap water at room temperature

· Ruler

Density of Rocks (Revised by University of Miami Science Made Sensible Fellows)

· Vegetable oil

· Karo syrup

· 1 can of coke

· 1 can of diet coke

· Aquarium/container to float cokes

· Rocks, four types, including pumice stone

· Plastic baggies or other container for rocks

· triple beam scales

· 500ml graduated cylinders

· Dry ice

· Container for dry ice demo

· Bubble wand and soap

· 1 large graduated cylinder (~1000ml)

· Food Coloring dye

· 250ml Flasks

· Eye droppers

· Paper towels

Mass, Volume, Density (Comprehensive Science 3 Advanced)

· Safety goggles

· 50 mL of isopropyl alcohol (colored red)

· 50 mL of water (colored blue)

· 50 mL of salt-water (colored green)

· Graduated cylinder

· Eye dropper

· Calculator

· Electronic balance or triple-beam balance

Precipitating Bubbles

· 5 grams calcium hydroxide powder

· One liter of water

· Filter paper

· Filter funnel

· Flasks or small bottles

· Straws

· Goggles

· 25 mL or 50 mL graduated cylinder

· 125 mL Erlenmeyer flasks

· Test–tube rack

· Aluminum foil

· Stop watch

· Hot Plate

Materials List (continued)

Greenhouse Gases in a Bottle

· Four: 500 mL clear water bottles with the label removed

· Identical thermometers for each soda bottle

· Opaque tape

· Source of carbon dioxide (CO2)-vinegar and baking powder

· Modeling clay Measuring spoons

· Balloons

· 500mL Erlenmeyer Flask

· 500 mL of room temperature water

Conservation of Mass

·

· Graduated Cylinder

· Erlenmeyer Flask

· Balloon

· Baking Soda

· Triple Beam Balance

· Spoon

Carbon Cycle Game

·

· 7 Dice

· 7 Station Signs

· 7 Station Movement Directions

· Carbon Cycle Passport for Each Student

· Carbon Atom Model for Each Student

· Blank Bar Graph for Each Student

The Martian Sun-Times

· Worksheets

· Computer with Internet access

· meter stick

· markers or colored pencils

· metric ruler

· scissors

· receipt paper rolls (adding machine tape) or old VHS tape

· Various spherical objects of different sizes (basketball, marbles, softball, tiny beads, soccer ball)

Imaginary Alien Life-forms

· Worksheets

· Creature Cards

Planetary Exploration and Extreme Life Forms (Differentiated Lab)

· computers with internet access

· construction paper

· books on the planets

· markers/crayons/colored pencils

Visualizing Our Solar System Scale Models (Differentiated Lab)

For Part 2

· meter sticks

· receipt paper rolls

· scissors

· markers, crayons, or colored pencils

For Part 1

· Various spherical objects of different sizes

· Grain of sand, pebble, golf ball, tennis ball

· Basketball, yoga ball, etc.

What Causes the Seasons?

· Globe of the Earth

· Tape

· Metric ruler

· Temperature probe or thermometer

· Lamp with 100-watt bulb

· Ring stand and utility clamp

· 20-cm Length of string

Lab Roles and Their Descriptions

Cooperative learning activities are made up of four parts: group accountability, positive interdependence, individual responsibility, and face-to-face interaction. The key to making cooperative learning activities work successfully in the classroom is to have clearly defined tasks for all members of the group. An individual science experiment can be transformed into a cooperative learning activity by using these lab roles.

Project Director (PD)

The project director is responsible for the group.

Roles and responsibilities:

· Reads directions to the group

· Keeps group on task

· Is the only group member allowed to talk to the teacher

· Shares summary of group work and results with the class

Materials Manager (MM)

The materials manager is responsible for obtaining all necessary materials and/or equipment for the lab.

Roles and responsibilities:

· The only person allowed to be out of his/her seat to pick up needed materials

· Organizes materials and/or equipment in the work space

· Facilitates the use of materials during the investigation

· Assists with conducting lab procedures

· Returns all materials at the end of the lab to the designated area

Technical Manager (TM)

The technical manager is in charge of recording all data.

Roles and responsibilities:

· Records data in tables and/or graphs

· Completes conclusions and final summaries

· Assists with conducting the lab procedures

· Assists with the cleanup

Safety Director (SD)

The safety director is responsible for enforcing all safety rules and conducting the lab.

Roles and responsibilities:

· Assists the PD with keeping the group on-task

· Conducts lab procedures

· Reports any accident to the teacher

· Keeps track of time

· Assists the MM as needed.

When assigning lab groups, various factors need to be taken in consideration;

Always assign the group members preferably trying to combine in each group a variety of skills. For example, you can place an “A” student with a “B”, a “C” and a “D” or an “F” student.

Evaluate the groups constantly and observe if they are on task and if the members of the group support each other in a positive way. Rotation of lab groups and members throughout the year is encouraged.

Laboratory Safety

Rules:

· Know the primary and secondary exit routes from the classroom.

· Know the location of and how to use the safety equipment in the classroom.

· Work at your assigned seat unless obtaining equipment and chemicals.

· Do not handle equipment or chemicals without the teacher’s permission.

· Follow laboratory procedures as explained and do not perform unauthorized experiments.

· Work as quietly as possible and cooperate with your lab partner.

· Wear appropriate clothing, proper footwear, and eye protection.

· Report all accidents and possible hazards to the teachers.

· Remove all unnecessary materials from the work area and completely clean up the work area after the experiment.

· Always make safety your first consideration in the laboratory.

Safety Contract:

I will:

· Follow all instructions given by the teacher.

· Protect eyes, face and hands, and body while conducting class activities.

· Carry out good housekeeping practices.

· Know where to get help fast.

· Know the location of the first aid and firefighting equipment.

· Conduct myself in a responsible manner at all times in a laboratory situation.

I, _______________________, have read and agree to abide by the safety regulations as set forth above and also any additional printed instructions provided by the teacher. I further agree to follow all other written and verbal instructions given in class.

Signature: ____________________________Date: ___________________

Pre-Lab Safety Worksheet and Approval Form

This form must be completed with the teacher’s collaboration before the lab.

Student Researcher Name: __________________________________________Period # _____

Title of Experiment: ____________________________________________________________

Place a check mark in front of each true statement below:

1. I have reviewed the safety rules and guidelines.

2. This lab activity involves one or more of the following:

Human subjects (Permission from participants required. Subjects must indicate

willingness to participate by signing this form below.)

Vertebrate Animals (requires an additional form)

Potentially Hazardous Biological Agents (Microorganisms, molds, rDNA,

tissues, including blood or blood products, all require an additional form.)

Hazardous chemicals (such as: strong acids or bases)

Hazardous devices (such as: sharp objects or electrical equipment)

Potentially Hazardous Activities (such as: heating liquids or using flames)

3. I understand the possible risks and ethical considerations/concerns involved in

this experiment.

4. I have completed an Experimental/Engineering Design Diagram.

Show that you understand the safety and ethical concerns related to this lab by responding to the questions below. Then, sign and submit this form to your teacher before you proceed with the experiment (use back of paper, if necessary).

A. Describe what you will be doing during this lab.

B. What are the safety concerns with this lab that were explained by your teacher?

How will you address them?

C. What additional safety concerns or questions do you have?

D. What ethical concerns related to this lab do you have?

How will you address them?

Student Researcher’s Signature/Date:Teacher Approval Signature:

__________________________________________________________________

Human Subjects’ Agreement to Participate:

___________________________________________________________

Printed Name/Signature/Date Printed Name/Signature/Date

____________________________________________________________

Printed Name/Signature/Date Printed Name/Signature/Date

Parts of a Lab Report

A Step-by-Step Checklist

A good scientist reflects on their work by writing a lab report. A lab report is a recap of what a scientist investigated. It is made up of the following parts.

Title (underlined and on the top center of the page)

Benchmarks Covered:

· Your teacher should provide this information for you. It is a summary of the main concepts that you will learn about by carrying out the experiment.

Problem Statement:

· Identify the research question/problem and state it clearly.

Potential Hypothesis (e.g.):

· State the hypothesis carefully. Do not just guess but try to arrive at the hypothesis logically and, if appropriate, with a calculation.

· Write down your prediction as to how the test variable (independent variable) will affect the outcome variable (dependent variable) using an “if” and “then” statement.

· If (state the test variable) is (choose an action), then (state the outcome variable) will (choose an action).

Materials:

· Record precise details of all equipment used

· For example: a balance weighing to +/- 0.001 g, a thermometer measuring from -10 to +110oC to an accuracy of +/- 0.1oC, etc.

· Record precise details of any chemicals used

· For example: 5 g of copper (II) sulfate pentahydrate CuSO4.5H2O(s).

Procedure:

· Do not copy the procedures from the lab manual or handout.

· Summarize the procedures; be sure to include critical steps.

· Give accurate and concise details about the apparatus and materials used.

Variables and Control Test:

· Identify the variables in the experiment. State those over which you have control. There are three types of variables.

1. Test Variable (Independent Variable): (also known as the tested variable) the factor that can be changed by the investigator (the cause).

2. Outcome Variable (Dependent Variable): (also known as the outcome variable) the observable factor of an investigation which is the result or what happened when the independent variable was changed.

3. Controlled variables (Constants): the other identified independent variables in the investigation that are kept constant or remain the same during the investigation.

· Identify the control test. A control lest is the separate experiment that serves as the standard for comparison to identify experimental effects, changes of the dependent variable resulting from changes made to the independent variable.

Data:

· Ensure that all data is recorded.

· Pay particular attention to significant figures and make sure that all units are stated.

· Present your results clearly. Often it is better to use a table or a graph.

· If using a graph, make sure that the graph has a title, both axis are labeled clearly, and that the correct scale is chosen to utilize most of the graph space.

· Record all observations.

· Include color changes, solubility changes, whether heat was evolved or taken in, etc.

Results:

· Ensure that you have used your data correctly to produce the required result in words and provide graphs.

· Include any other errors or uncertainties which may affect the validity of your result.

Conclusion and Evaluation:

· A conclusion statement answers the following 7 questions in at least three paragraphs.

· First Paragraph: Introduction

1. What was investigated?

a. Describe the problem.

2. Was the hypothesis supported by the data?

a. Compare your actual result to the expected result (either from the literature, textbook, or your hypothesis)

b. Include a valid conclusion that relates to the initial problem or hypothesis.

3. What were your major findings?

a. Did the findings support or not support the hypothesis as the solution to the restated problem?

b. Calculate the percentage error from the expected value.

· Middle Paragraphs: These paragraphs answer question 4 and discusses the major findings of the experiment using data.

4. How did your findings compare with other researchers?

a. Compare your result to other students’ results in the class.

· The body paragraphs support the introductory paragraph by elaborating on the different pieces of information that were collected as data that either supported or did not support the original hypothesis.

· Each finding needs its own sentence and relates back to supporting or not supporting the hypothesis.

· The number of body paragraphs you have will depend on how many different types of data were collected. They will always refer back to the findings in the first paragraph.

· Last Paragraph: Conclusion

5. What possible explanations can you offer for your findings?

a. Evaluate your method.

b. State any assumptions that were made which may affect the result.

6. What recommendations do you have for further study and for improving the experiment?

a. Comment on the limitations of the method chosen.

b. Suggest how the method chosen could be improved to obtain more accurate and reliable results.

7. What are some possible applications of the experiment?

a. How can this experiment or the findings of this experiment be used in the real world for the benefit of society?

Parts of a Lab Report Reminder

Step 1: Stating the Purpose/Problem

· What do you want to find out? Write a statement that describes what you want to do. It should be as specific as possible. Often, scientists read relevant information pertaining to their experiment beforehand. The purpose/problem will most likely be stated as a question such as:

“What are the effects of _________ on ___________?”

Step 2: Defining Variables

· TEST VARIABLE (TV) (also called the independent variable) – The variable that is changed on purpose for the experiment; you may have several levels of your test variable.

· OUTCOME VARIABLE (OV) (also called the dependent variable) – The variable that acts in response to or because of the manipulation of the test variable.

· CONTROLLED VARIABLES (CV) – All factors in the experiment that are NOT allowed to change throughout the entire experiment. Controlling variables is very important to assure that the results are due only to the changes in the test variable; everything (except the test variable) must be kept constant in order to provide accurate results.

Step 3: Forming a Hypothesis

· A hypothesis is an inferring statement that can be tested.

· The hypothesis describes how you think the test variable will respond to the outcome variable. (i.e., If….., then……)

· It is based on research and is written prior to the experiment. Never change your hypothesis during the experiment.

· For example: If the temperature increases, then the rate of the reaction will increase.

· Never use “I,” “we,” or “you” in your hypothesis (i.e. I believe or I think that…)

· It is OK if the hypothesis is not supported by the data. A possible explanation for the unexpected results should be given in the conclusion

Step 4: Designing an Experimental Procedure

· Select only one thing to change in each experimental group (test variable).

· Change a variable that will help test the hypothesis.

· The procedure must tell how the variable will be changed (what are you doing?).

· The procedure must explain how the change in the variable will be measured.

· The procedure should indicate how many trials would be performed (usually a minimum of 3-4 for class experiments).

· It must be written in a way that someone can copy your experiment, in step by step format.

Step 5: Results (Data)

· Qualitative Data is comprised of a description of the experimental results (i.e. larger, faster….).

· Quantitative Data is comprised of results in numbers (i.e. 5 cm, 10.4 grams)

· The results of the experiment will usually be compiled into a table/chart for easy interpretation.

· A graph of the data (results) may be made to more easily observe trends.

Step 6: Conclusion

The conclusion should be written in paragraph form. It is a summary of the experiment, not a step-by-step description. Does the data support the hypothesis? If so, you state that the hypothesis is accepted. If not, you reject the hypothesis and offer an explanation for the unexpected result. You should summarize the trend in data in a concluding statement (ex: To conclude, the increase in temperature caused the rate of change to increase as shown by the above stated data.). Compare or contrast your results to those from similar experiments. You should also discuss the implications for further study. Could a variation of this experiment be used for another study? How does the experiment relate to situations outside the lab? (How could you apply it to real world situations?)

Student’s name: _____________________________________________ Date: ________________Period: _______

Experimental Design Diagram

This form should be completed before experimentation.

Title:

Problem Statement:

Null Hypothesis:

Research Hypothesis:

Test Variable

(Independent Variable)

Number of Tests:

Subdivide this box to specify each variety.

Control Test:

# of Trials per Test:

Outcome Variable

(Dependent Variable)

Controlled Variables

1.

2.

3.

4.

5.

6.

Experimental Design Diagram Hints:

Title: A clear, scientific way to communicate what you’re changing and what you’re measuring is to state your title as, "The Effect of ____________on__________." The tested variable is written on the first line above and the outcome variable is written on the second line.

Problem Statement: Use an interrogative word and end the sentence with a question mark. Begin the sentence with words such as: How many, How often, Where, Will, or What. Avoid Why.

Null Hypothesis: This begins just like the alternate hypothesis. The sentence should be in If ............, then........... form. After If, you should state the TV, and after the then, you should state that there will be no significant difference in the results of each test group.

Research Hypothesis: If ____________(state the conditions of the experiment), then ____________(state the predicted measurable results). Do not use pronouns (no I, you, or we) following If in your hypothesis.

Test Variable (TV): This is the condition the experimenter sets up, so it is known before the experiment (I know the TV before). In middle school, there is usually only one TV. It is also called the independent variable, the IV.

Number of Tests: State the number of variations of the TV and identify how they are different from one another. For example, if the TV is "Amount of Calcium Chloride" and 4 different amounts are used, there would be 4 tests. Then, specify the amount used in each test.

Control Test: This is usually the experimental set up that does not use the TV. Another type of control test is one in which the experimenter decides to use the normal or usual condition as the control test to serve as a standard to compare experimental results against. The control is not counted as one of the tests of the TV. In comparison experiments there may be no control test.

Number of Trials: This is the number of repetitions of one test. You will do the same number of repetitions of each variety of the TV and also the same number of repetitions of the control test. If you have 4 test groups and you repeat each test 30 times, you are doing 30 trials. Do not multiply 4 x 30 and state that there were 120 trials.

Outcome Variable(s): This is the result that you observe, measure and record during the experiment. It’s also known as the dependent variable, OV. (I don’t know the measurement of the OV before doing the experiment.) You may have more than one OV.

Controlled Variables or Variables Held Constant: Controlled Variables (Constants) are conditions that you keep the same way while conducting each variation (test) and the control test. All conditions must be the same in each test except for the TV in order to conclude that the TV was the cause of any differences in the results. Examples of Controlled Variables (Constants): Same experimenter, same place, time, environmental conditions, same measuring tools, and same techniques.

CONCLUSION WRITING

Claim, Evidence and Reasoning

Students should support their own written claims with appropriate justification. Science education should help prepare students for this complex inquiry practice where students seek and provide evidence and reasons for ideas or claims (Driver, Newton and Osborne, 2000). Engaging students in explanation and argumentation can result in numerous benefits for students. Research shows that when students develop and provide support for their claims they develop a better and stronger understanding of the content knowledge (Zohar and Nemet, 2002).

When students construct explanations, they actively use the scientific principles to explain different phenomena, developing a deeper understanding of the content. Constructing explanations may also help change students’ view of science (Bell and Linn, 2000). Often students view science as a static set of facts that they need to memorize. They do not understand that scientists socially construct scientific ideas and that this science knowledge can change over time. By engaging in this inquiry practice, students can also improve their ability to justify their own written claims (McNeill et al., 2006).

Remember when providing evidence to support a claim, the evidence must always be:

· Appropriate

· Accurate

· Sufficient

The rubric below should be used when grading lab reports/conclusions to ensure that students are effectively connecting their claim to their evidence to provide logical reasons for their conclusions.

Base Explanation Rubric

Component

Level

0

1

2

Claim - A conclusion that answers the original question.

Does not make a claim, or makes an inaccurate claim.

Makes an accurate but incomplete claim.

Makes an accurate and complete claim.

Evidence – Scientific data that supports the claim. The data needs to be appropriate and sufficient to support the claim.

Does not provide evidence, or only provides inappropriate evidence (evidence that does not support the claim).

Provides appropriate but insufficient evidence to support claim. May include some inappropriate evidence.

Provides appropriate and sufficient evidence to support claim.

Reasoning – A justification that links the claim and evidence. It shows why the data count as evidence by using appropriate and sufficient scientific principles.

Does not provide reasoning, or only provides reasoning that does not link evidence to claim

Provides reasoning that links the claim and evidence. Repeats the evidence and/or includes some – but not sufficient – scientific principles.

Provides reasoning that links evidence to claim. Includes appropriate and sufficient scientific principles.

McNeill, K. L. & Krajcik, J. (2008). Inquiry and scientific explanations: Helping students use evidence and reasoning. In Luft, J., Bell, R. & Gess-Newsome, J. (Eds.). Science as inquiry in the secondary setting. (p. 121-134). Arlington, VA: National Science Teachers Association Press.

Engineering Design Process

Step 1

Identify the Need or Problem

Step 3

Develop Possible Solution(s)

Step 2

Research the Need or Problem

Step 6

Test and Evaluate the Solution(s)

Step 7

Communicate the Solution(s)

Step 8

Redesign

Step 5

Construct a Prototype

Step 4

Select the Best Possible Solution(s)

1. Identify the need or problem

2. Research the need or problem

a. Examine current state of the issue and current solutions

b. Explore other options via the internet, library, interviews, etc.

c. Determine design criteria

3. Develop possible solution(s)

a. Brainstorm possible solutions

b. Draw on mathematics and science

c. Articulate the possible solutions in two and three dimensions

d. Refine the possible solutions

4. Select the best possible solution(s)

a. Determine which solution(s) best meet(s) the original requirements

5. Construct a prototype

a. Model the selected solution(s) in two and three dimensions

6. Test and evaluate the solution(s)

a. Does it work?

b. Does it meet the original design constraints?

7. Communicate the solution(s)

a. Make an engineering presentation that includes a discussion of how the solution(s) best meet(s) the needs of the initial problem, opportunity, or need

b. Discuss societal impact and tradeoffs of the solution(s)

8. Redesign

a. Overhaul the solution(s) based on information gathered during the tests and presentation

Source(s): Massachusetts Department of Elementary and Secondary Education

INQUIRY LAB: PHYSICAL PROPERTIES OF MATTER

Florida Next Generation Sunshine State Standards Benchmark(s):

SC.8.P.8.4 Classify and compare substances on the basis of characteristic physical properties that can be demonstrated or measured; for example, density, thermal or electrical conductivity, solubility, magnetic properties, melting and boiling points, and know that these properties are independent of the amount of the sample. (AA - Also assesses SC.8.P.8.3.)

SC.7.N.1.2 Differentiate replication (by others) from repetition (multiple trials). (AA)

Materials:

•Sugar•Wood chips•Iron (fillings or staples)•Sand•Water•Magnet•Coffee filter•Graduated cylinder•Triple beam balance•Thermometer•Beaker•Hot plate

Engage:

“Mystery balloons”: place common objects or materials (penny, key, battery, flour, etc.) in deflated rubber balloons and tie. Have students use their senses to try to identify the contents based on physical properties.

Teacher shows Studyjams-Properties of Matter on the SmartBoard.

Part 1: Separating Matter

Objective: Students will design their own method to separate contents of a mixture based on the physical properties of each substance.

Pre-lab set up (by teacher): Combine sugar, sand, wood, and iron into a beaker for each lab group.

Procedure: Record the steps you take to separate the substances in the mixture. Remember to be as specific as possible so that your results are replicable!!

Answer Key:

The possible steps are written in red. Students should create their OWN procedures.

1. Run magnet through mixture to separate iron based on magnetism.

2. Pour water over mixture to separate wood based on density. Wood is less dense than water.

3. Use filter to remove sand from mixture since sand is not soluble in water.

4. Use hot plate to separate sugar from water. Water will evaporate first since it has a lower boiling point than sugar.

Conclusion Questions:

1. Summarize: How did you separate the materials in the beaker? Answers will vary

2. Why is it important for scientists to write detailed procedures? So that other scientists can replicate the study and verify the validity of the results.

3. Why didn’t you measure the melting points of sand, wood, or iron in this lab? Their melting points are too high to safely observe in this lab.

4. Would the physical properties of a material change if the size of the material is changed? Explain. No, physical properties are independent of sample size

5. Did you have to completely alter /chemically change any of the materials to measure their physical properties? Explain. No, can measure physical properties without changing the substance.

6. Scientists often find mysterious materials. Explain how physical properties are important for identifying unknown substances. Scientists can use the various physical properties such as melting point, boiling point, thermal or electrical conductivity, magnetism, density and solubility of the unknown substance to compare to known substances and correctly identify the substance or discover a new substance.

Name: ___________________________________________ Period: ________ Date: _________

Separating Matter

Procedure: Record the steps you take to separate the substances in the mixture. Remember to be as specific as possible so that your results are replicable!

Material

Physical Property used to separate from mixture

Explanation

Sugar

Sand

Wood

Iron

Part 2: Measuring physical properties

Student task: Use your observations and the tools provided to measure the physical properties of the substances you separated in Part 1.

Material:

Sugar

Sand

Wood

Iron

Color:

Texture:

Odor:

Soluble in water?

Density: (Density= mass/ volume)

Mass:

Volume:

Density=

Mass:

Volume:

Density=

Mass:

Volume:

Density=

Mass:

Volume:

Density=

Magnetic?

Melting point:

X

X

X

Conclusion Questions:

7. Summarize: How did you separate the materials in the beaker?

8. Why is it important for scientists to write detailed procedures?

9. Why didn’t you measure the melting points of sand, wood, or iron in this lab?

10. Would the physical properties of a material change if the size of the material is changed? Explain.

11. Did you have to completely alter /chemically change any of the materials to measure their physical properties? Explain.

12. Scientists often find mysterious materials. Explain how physical properties are important for identifying unknown substances.

DENSITY OF ROCKS

Adapted from: www.sciencenet.org.uk/.../Chemistry/ StructBond/c00195b.html

Florida Next Generation Sunshine State Standards Benchmark(s): SC.8.N.1.1 Define a problem from the eighth grade curriculum using appropriate reference materials to support scientific understanding, plan and carry out scientific investigations of various types, such as systematic observations or experiments, identify variables, collect and organize data, interpret data in charts, tables, and graphics, analyze information, make predictions, and defend conclusions. (AA)SC.8.P.8.3 – Explore and describe the densities of various materials through measurement of their masses and volumes. Assessed as SC.8.P.8.4 – Classify and compare substances on the basis of characteristic physical properties that can be demonstrated or measured; for example, density, thermal or electrical conductivity, solubility, magnetic properties, melting and boiling points, and know that these properties are independent of the amount of the sample.

Background Information for the teacher:Density is a basic physical property of any sample of matter. It is much more important than other physical properties such as size or shape, in that the numerical value of density for a pure substance at a particular temperature and pressure is a constant and never changes! The density may be determined in the laboratory if the mass and volume of a sample can be determined. Density may be calculated by dividing the mass by the volume (d = m / V). It also may be thought of as the ratio of the mass to the volume. The density of water is important to know. It is 1.0 g/mL at 40C.

In this experiment, the student will measure the mass, volume, and the length of several rocks. They will then use their data to explore the relationship between the mass and volume of the rocks and calculate their density.

Materials

·

· Graduated cylinder

· 250 mL beaker

· medicine dropper

· food coloring ( not essential but helpful)

· 100 mL Graduated cylinder

· Eye dropper

· Calculator

· Electronic balance or triple-beam balance

· 5 different type of rocks

· Tap water at room temperature

· ruler

Teacher Pre-Lab Preparation and Presentation:

1. Color the water by adding a few drops of food coloring.

Engage: (students should develop procedures similar to the ones in the Explore section)

Teacher will engage students in discussion with the following questions to determine students’ pre-conceptions. Record responses on the board:

a) Observe the 5 rocks and estimate which rock could have the largest mass, volume and density?

b) Will the largest rock (largest volume) have the largest mass?

c) What is density? What do you need to know to calculate density?

d) Mass/Volume is a ratio which represents density.

e) Predict which rock would have the greatest density and smallest density.

f) Would the largest rock be the most dense and the smallest rock the least dense?

g) Would all of these rocks sink in water?

Explore (students should come up these procedures and how they can be completed in the engagement)

1. On the electronic or triple beam balance mass each rock in grams (g). Record your measurement in the data table

2. Pour 50 mL of the colored water into the graduated cylinder. Use the dropper to get the exact amount of 50 mL.

3. Drop the first rock into the graduated cylinder and determine the volume of the rock in milliliter (mL) using the water displacement method. Record your measurement in the data table.

Final volume (water with rock) – Initial volume (50 mL of water) = Volume of the rock (use cm3 since rocks are a solid and 1 mL = 1 cm3). To get a precise measurement, place the cylinder on a flat surface, bring your “eye” down to the level of the liquid, and read the bottom of the meniscus.

4. Repeat step 3 with the other 4 rocks. Record your measurement (cm3) in the data table.

5. Finally calculate the density of each rock, using the following formula:

Density = Mass/Volume

Using the unit for density (g/cm3)

6. Record your measurement in the data table.

Data Table: Density of Rocks

Rock

Mass (g)

Final-Initial=

Volume of rock (cm3)

Density (g/cm3)

1

2

3

4

5

Figure 1

Densities of Some Common Rocks

Rock

Density

Andesite

2.5 - 2.8

Basalt

2.8 - 3.0

Coal

1.1 - 1.4

Diabase

2.6 - 3.0

Diorite

2.8 - 3.0

Dolomite

2.8 - 2.9

Gabbro

2.7 - 3.3

Gneiss

2.6 - 2.9

Granite

2.6 - 2.7

Gypsum

2.3 - 2.8

Limestone

2.3 - 2.7

Marble

2.4 - 2.7

Mica schist

2.5 - 2.9

Peridotite

3.1 - 3.4

Quartzite

2.6 - 2.8

Rhyolite

2.4 - 2.6

Rock salt

2.5 - 2.6

Sandstone

2.2 - 2.8

Shale

2.4 - 2.8

Slate

2.7 - 2.8

Explain

Analysis Questions:

1. Which variable is considered the test variable (independent variable) in this lab activity?

2. Which variable (s) is considered the outcome variable (dependent variable) in this lab activity?

3. If the mass of the rock increases, what could happen to the density of each sample?

4. If the volume of the rock increases, what would happen to the density of each sample?

5. Analyze your data: What do you observe about the relationship between mass and volume for the rocks with the larger densities and smaller densities? Give examples from the lab in your explanation.

6. In terms of density, differentiate between an object which floats in water and an object which sinks in water.

7. Show how one would set up a ratio to determine the mass of a substance with a density of 8.4g/mL and a volume of 2.0 mL. Determine the mass.

8. Show how one would set up a ratio to determine the volume of a substance with a density of 4.0 g/mL and a mass of 8.0 g. Determine the volume.

9. Based on the results of this lab, explain how unknown substances can be identified or distinguished from one another by using their densities.

Bonus question:

10. Density of water is 1 g/ml or 1.0 g/cm3). What is the volume of a sample of water if the mass is 6g? Explain why this is so easy to figure out (think ratio).

www.sciencenet.org.uk/.../Chemistry/ StructBond/c00195b.html

Elaborate:

1. Provide students with the following data derived from a set of Density Blocks

Figure 2

Densities of Common Substances

Source: Teacher Developed – Classroom Tested

Substance

Density (g/cm3)

Acrylic

1.1 – 1.2

Aluminum

2.7

Brass

8.4 – 8.8

Copper

8.96

Oak

0.60 – 0.90

Pine

0.35 – 0.50

Polypropylene

0.91 – 0.94

PVC

1.39 – 1.42

Steel

7.9

Water

1.0

2. Provide students with the following information: You have been given blocks of equal volume. You may want to provide the Density Block samples or have students make cubes 2.54 cm x 2.54 cm x 2.54 cm

3. Based on the densities of the various substances listed in the data table above, ask students to make predictions whether the block made of the various materials would sink or float in water.

Block

Prediction (sink or float)

Observation (sink or float)

Acrylic

Aluminum

Brass

Copper

Oak

Pine

Polypropylene

PVC

Steel

Acrylic

Evaluate

If two blocks of pine were stacked on top of each other, would they sink or float? Explain.

Extensions:

1. Students will explore the density of different liquids and/or solutions, e.g. 5%, 10%, 15% saltwater solution. Discover the relationship between density and the solute concentration.

Possible Answers

Explain

Analysis Questions:

1. Which variable is considered the test variable (independent) variable in this lab activity? Type of rock

2. Which variable (s) is considered the outcome variable (dependent) variable in this lab activity? density

3. If the mass of the rock increases, what could happen to the density of each sample? Increase if volume stays same

4. If the volume of the rock increases, what would happen to the density of each sample? It would stay the same because the mass would also increase

5. Analyze your data: What do you observe about the relationship between mass and volume for the rocks with the larger densities and smaller densities? Give examples from the lab in your explanation. Larger densities have larger mass compared to the object’s volume; smaller densities have larger volume compared to the mass. Examples will vary

6. In terms of density, differentiate between an object which floats in water and an object which sinks in water. An object that floats in water is less dense than the water or less than 1 g/cm3 . An object that sinks has a greater density than water.

7. Show how one would set up a ratio to determine the mass of a substance with a density of 8.4g/mL and a volume of 2.0 mL. Determine the mass. 8.4g/mL = ?g/2.0 mL mass = 16.8 g

8. Show how one would set up a ratio to determine the volume of a substance with a density of 4.0 g/mL and a mass of 8.0 g. Determine the volume. 4.0 g/mL = 8.0 g/?mL volume = 2 mL

9. Based on the results of this lab, explain how unknown substances can be identified or distinguished from one another by using their densities. All substances have a specific density. If the mass and volume can be determined, then the substance can be found by comparing with substances of known densities.

Bonus question:

10. Density of water is 1 g/ml or 1.0 g/cm3). What is the volume of a sample of water if the mass is 6g? Explain why this is so easy to figure out (think ratio). The density of water is a 1:1 ratio 6 g would mean 6 mL

Evaluate

If two blocks of pine were stacked on top of each other, would they sink or float? Explain: The blocks would float. The wood is still less dense than water. For example, if the mass doubles, so does the volume, keeping the density the same.

Note: Use real examples for students to measure and test.

www.sciencenet.org.uk/.../Chemistry/ StructBond/c00195b.html

Additional Background Information - Density of Rocks

Source: http://oceanleadership.org/files/309_Density_Oceanic_Crust.pdf

Certain properties of a substance are both distinctive and relative easy to determine. Density, the ratio between a sample’s mass and volume at specific temperature and pressure (like standard ambient temperature and pressure), is one such property. Regardless of the size of a sample, the density of a substance will always remain the same.

The density of a rock sample can, therefore, be used in the identification process.

Typical densities for some types of rock are: - Basalt 3 g/cm3 (187 lbm/ft3) - Granite 2.7 g/cm3 (169 lbm/ft3) - Sandstone 2.3 g/cm3 (144 lbm/ft3)

Some rocks are heavier and others much lighter than those listed above. For example, Pumice is a rock formed from solidified foamy volcanic lava. It is full of spaces full of gas, rather like a sponge. Some examples of Pumice are half the density of water, at 0.5 g/cm3. Density varies significantly among different rock types because of differences in mineralogy and porosity. Knowledge of the distribution of underground rock densities can assist in interpreting subsurface geologic structure and rock type.

While density may vary only slightly from rock to rock, detailed sampling and correlation with other factors like depth may reveal important information about the history of a core, or may help to improve the use of seismic profiles. The average density of oceanic crust is 3.0 g/cm3 while continental crust has an average density of 2.7 g/cm3.

STUDENT HANDOUT

DIFFERENTIATED INSTRUCTION: OPEN INQUIRY

density of matter

Objectives/Purpose:

· Determine the physical properties of matter including the density of irregular solids.

· Demonstrate that regardless of the size of a sample, the density of a substance will always remain the same.

· Classify and compare substances on the basis of characteristic physical properties that can be demonstrated or measured

Demonstrate Achievement of the following Goals:

· Develop a problem statement based on a physical property of matter and the size of the sample that you would like to investigate.

· State your hypothesis.

· Design an experiment to test your hypothesis.

· Carry out the experiment you designed.

· Submit a completed lab report to your teacher.

· Use the “Claim, Evidence & Reasoning” rubric to defend your claims when writing your conclusion.

DENSITY OF ROCKS (Differentiated Lab)

Revised by: University of Miami – Science Made Sensible Fellows

Florida Sunshine State Next Generation Standards Benchmark: SC.8.P.8.4 Classify and compare substances on the basis of characteristic physical properties that can be demonstrated or measured for example, density, thermal or electrical conductivity, solubility, magnetic properties, melting and boiling points, and know that these properties are independent of the amount of the sample. (AA)

SC.8.P.8.3 Explore and describe the densities of various materials through measurement of their masses and volumes.

Background Information for the teacher:

Density is a basic physical property of any sample of matter. It is much more important than other physical properties such as size or shape, in that the numerical value of density for a pure substance at a particular temperature and pressure is a constant and never changes! The density may be determined in the laboratory if the mass and volume of a sample can be determined. Density may be calculated by dividing the mass by the volume (d = m / V). It also may be thought of as the ratio of the mass to the volume. The density of water is important to know. It is 1.0 g/mL at 4oC.

In this experiment, the student will measure the mass, volume, and the length of several rocks. They will then use their data to explore the relationship between the mass and volume of the rocks and calculate the rocks’ density.

Time Frame: 1-1.5 hours

Materials:

Demonstrations

·

· Vegetable oil

· Karo syrup

· 1 can of coke

· 1 can of diet coke

· Aquarium/container to float cokes

· Dry ice

· Container for dry ice demo

· Bubble wand and soap

· 1 large graduated cylinder (~1000ml)

Lab Activity

·

· Rocks, four types, including pumice stone

· Plastic baggies or other container for rocks

· triple beam scales

· 500ml graduated cylinders

· 250ml Flasks

· Eye droppers

· Paper towels

· Food Coloring dye (for demo also)

Pre-lab preparation:

1) Color the water/oil/karo syrup demo with food coloring

2) Select 4 rocks with very different densities as available. One should be pumice stone. Alter the comic strip and student worksheet (clues) so that the “evidence” rock density matches the density of one of the types of rock you have available.

3) Gather and prepare demonstration supplies as desired.

Engage:

1) Engage the students by discussing the topic of density as a class, explaining how it is a relationship between mass and volume.

2) Perform one or more of the following demonstrations:

a. Water/Oil/Syrup layering: Discuss with the class what you will be doing, and have them make predictions of how the three liquids will layer in the 1000ml graduated cylinder. Start with ~250ml of colored water in the cylinder, then add vegetable oil (~100ml) and finally add Karo syrup (~100ml). Discuss why the fluids became layered.

b. Coke vs. Diet Coke: Explain what you are going to do, and have your class predict whether the sodas will sink or float. In a clear container (aquarium) filled with water, place a regular coke or comparable soda. Discuss why the soda sank. Next, add the diet coke (it will float). Discuss why a can with the exact same volume will float because it has less mass and therefore is less dense.

c. Dry ice/bubbles: In a container that is at least 12 inches deep, place the dry ice. Add some water to speed up the sublimation process and make the gas visible to the students. Then, blow bubbles gently on top of the CO2 gas. Discuss with your class why the bubbles did not sink through the CO2, and how density applies to gases also. (this is also useful at the end of the lab as they elaborate on the concept of density)

3) Engage the students further by reading the “CSI: Following the Hard Evidence” comic (source: http://www.pixton.com/SciMadeSensible).

Explore:

1) Give the student all the supplies and the procedures worksheet. Discuss the concept of volume displacement for determining the volume of non-geometric items.

2) Have student complete the procedures while you assist and answer questions. You may need to help them measure the volume of the pumice stone by pushing it completely under the surface of the water using a pencil.

Explain:

1) Have students complete the analysis questions at the end of the lab.

2) Discuss any questions as a class.

Elaborate/Extension:

1) Students can explore the density of objects with identical masses, but different volumes. Discover the relationship among mass, volume, and density.

2) Students can explore the density of different liquids and/or solutions, e.g. 5%, 10%, 15% saltwater solution. Discover the relationship between density and the solute concentration.

3) This is a good time to do the dry ice demo in order to elaborate that the property density applies to gases also.

C.S.I.

Density of Rocks: Following the HARD EVIDENCE

Goal: Determine the densities of 4 different types of rocks in order to match the “hard evidence” found at the crime scene.

Overview: The density of each rock will be calculated by using volume displacement and measuring mass

Procedures

1) Look at the rocks and make a prediction about which one you think is the most dense or the least dense. Record your hypothesis, independent variable, and dependent variable, controlled variables and control.

2) Remove your rocks from the evidence bag.

3) Measure the mass of each rock on the balance, record it on this worksheet.

4) Pour 150ml of water from the 500ml beaker into the graduated cylinder. Use the dropper to adjust it exactly to 150ml. This is the INITIAL VOLUME.

5) Place one rock into the graduated cylinder, then determine the volume of water in the cylinder by looking at the BOTTOM OF THE MENISCUS. Record this FINAL VOLUME on your worksheet.

6) Remove the rock by pouring the water back into the beaker and catching the rock with one hand so it doesn’t break the glass. Try not to spill!!

7) Refill the graduated cylinder to 150ml, add the next rock, measure the volume, and record it on your worksheet. Repeat for the third and fourth rocks, drying them with a paper towel and putting them back into their bags.

8) Calculate the volume of each rock by subtracting the initial volume of water (150ml) from the final volume of the water with the rock. Record this on your worksheet.

9) Calculate the density of each rock on the worksheet (Density= Mass/Volume).

10) Answer the questions under the data table on your worksheet and write a conclusion.

CLUES:

1) The detectives found a rock at the crime scene that had a density of _____ grams/cm3

2) There are three suspects, each live in an area with a different type of rock.

3) The equation for density is: density= mass/volume

Data Table

Rock

Mass (g)

Final Volume

(water +rock)

Rock Volume (final volume- initial volume)

Density (D=m/v)

Creepy Carl

Suspicious Susan

Naughty

Nathan

Police Station

Questions:

1) Which rock most closely matched the density of the evidence found at the crime scene?

2) Did all the rocks sink? If not, what can you tell about the density of that rock without doing any calculations?

3) For the rock that didn’t sink, if you put a larger sample in the water, would it sink? Why or why not?

4) If you start with 100ml of water, how many grams of Naughty Nathan’s rock would you need to add to your graduated cylinder to increase the volume by 100ml? (remember the equation for density is density=mass/volume, use the density you calculated above)

5) If the mass of the rock increases, what could happen to the volume of each sample?

6) If the volume of the rock increases, what could happen to the mass of each sample?

7) Explain density in terms of a ratio. Give examples from the lab in your explanation.

8) What is the volume of a sample of water if the mass is 6.7g? Explain why this is so easy to figure out.

9) Show how one would set up a ratio to determine the mass of a substance with a density of 5.6g/mL and a volume of 3.7 mL. Then determine the mass.

10) Show how one would set up a ratio to determine the volume of a substance with a density of 2.6 g/mL and a mass of 5.5 g. Then determine the volume.

Conclusion:

Write a conclusion using the “Claim, Evidence and Reasoning” format.MASS, VOLUME, DENSITY

(Comprehensive Science 3 Advanced)

Florida Next Generation Sunshine State Standards Benchmark: SC.8.N.1.1 Define a problem from the eighth grade curriculum using appropriate reference materials to support scientific understanding, plan and carry out scientific investigations of various types, such as systematic observations or experiments, identify variables, collect and organize data, interpret data in charts, tables, and graphics, analyze information, make predictions, and defend conclusions. (AA)SC.8.P.8.3 – Explore and describe the densities of various materials through measurement of their masses and volumes. Assessed as SC.8.P.8.4 – Classify and compare substances on the basis of characteristic physical properties that can be demonstrated or measured; for example, density, thermal or electrical conductivity, solubility, magnetic properties, melting and boiling points, and know that these properties are independent of the amount of the sample. (AA)

Background Information:

Density is a basic physical property of any sample of matter. It is much more important than other physical properties such as size or shape, in that the numerical value of density for a pure substance at a particular temperature and pressure is a constant and never changes! The density may be determined in the laboratory if the mass and volume of a sample can be determined. Density may be calculated by dividing the mass by the volume (d = m / V). It also may be thought of as the ratio of the mass to the volume. The density of water is important to know. It is 1.0 g/mL at 4 ºC.

In this experiment, the students will measure the mass and volume of several materials. They will then use their data to explore the relationship between the mass and volume of the materials and calculate their density.

Literature Connection: “Archimedes and the King’s Crown”

Time Frame: 1 hour

Materials (per pair of students):

Safety gogglesGraduated cylinder

50 mL of isopropyl alcohol (colored red)Eye dropper

50 mL of water (colored blue)Calculator

50 mL of salt-water (colored green) Electronic balance or triple-beam balance

Procedure

Part A: Teacher Pre-Lab Preparation and Presentation

1. Color the isopropyl alcohol red by adding a few drops of red food coloring.

2. Color the water blue by adding a few drops of blue food coloring.

3. Prepare a saltwater solution by mixing four parts water to one part salt by volume. Color the solution green using a few drops of green food coloring.

4. Show the students the three solutions and ask them to suggest a way to compare the masses of the three liquids.

5. Guide the discussion towards the realization that in order to compare the masses, equal volumes would have to be massed. Ask students to predict how the masses of the different liquids would be vary if the volume of each liquid is the same. Based on their predictions, have students formulate a hypothesis.

6. The topic of density as the relationship between mass and volume can now be introduced.

Part B: Student Procedure

1. On the electronic balance, mass the graduated cylinder and press "tare" to subtract the mass. If you are using a triple beam balance, mass the graduated cylinder and record this mass to the nearest 0.01g. Record the mass of the empty cylinder in the Data Table.

2. Pour 10 mL of the red liquid into the graduated cylinder. Use an eyedropper to get the exact amount of 10.0 mL.

3. To get a precise measurement, place the cylinder on a flat surface, bring your “eye” down to the level of the liquid, and read the bottom of the meniscus.

4. Determine the mass of the 10.0 mL by reading the electronic balance directly, or if using a triple- beam balance, record the total mass (cylinder + liquid) in the Data Table. Then subtract the mass of the empty graduated cylinder from the mass of the cylinder and sample of liquid.

5. Record the mass of the sample of liquid on the Data Table in the appropriate location, e.g. Red Liquid, volume of 10.0 mL.

6. Calculate the density of the liquid by dividing the mass by the volume (10 mL).

7. Record the density on the Data Table in the appropriate location, i.e. Red Liquid; volume of 10.0 mL.

8. Add another 10.0 mL to the cylinder. You should now have a total of 20.0 mL (10 mL + 10 mL).

9. Determine the mass of the 20.0 mL by reading the electronic balance directly, or if using a triple- beam balance, record the total mass CL (cylinder + liquid) record in the Data Table.

10. Then subtract the mass of the empty graduated cylinder (CE) from the mass of the cylinder and sample of liquid (CL). Record the mass of the sample of .liquid on the Data Table

11. Find the density again by dividing the mass by 20.0 mL and record it on the Data Table.

12. Keep adding 10.0 mL of the red liquid, recording the mass and calculating the density by dividing the mass by the amount of liquid in the cylinder until a total of 50.0 mL of the red liquid has been used.

13. Repeat the procedure for each of the other liquids, finding mass and density.

14. Graph mass (y-axis) vs. volume (x-axis) for each liquid on the graph paper provided. Use a different color for each of the liquid solutions.

15. Draw a line of “best-fit” for the points of each solution.

Data Analysis

Data Table for Red Liquid

Volume

(mL)

Mass of Empty Cylinder

CE

(g)

Mass of Cylinder and Sample of Liquid

CL

(g)

Mass of Sample of Liquid

CL- CE

(g)

Density (g/mL)

10.0

20.0

30.0

40.0

50.0

Data Table for Blue Liquid

Volume (mL)

Mass of Empty Cylinder

CE

(g)

Mass of Cylinder and Sample of Liquid

CL

(g)

Mass of Sample of Liquid

CL- CE

(g)

Density (g/mL)

10.0

20.0

30.0

40.0

50.0

Data Table for Green Liquid

Volume (mL)

Mass of Empty Cylinder

CE

(g)

Mass of Cylinder and Sample of Liquid

CL

(g)

Mass of Sample of Liquid

CL- CE

(g)

Density (g/mL)

10.0

20.0

30.0

40.0

50.0

Analysis Questions:

1. Which variable, mass or volume, is considered the test variable (independent variable) in this experiment?

2. Which variable, mass or volume is considered the outcome variable (dependent variable) in this experiment?

3. As the volume increases, what happens to the mass of each sample?

4. Compare your density calculations for the red liquid. Should the density be the same in each instance? Explain your answer. Will this also be true for the blue and green liquids?

5. Analyze your data and determine which liquid is most dense and which one is least dense. Focusing on the mass and volume of each liquid. Identify what the relationship is between mass and volume in terms of density.

6. Predict what would happen to the liquids, if you carefully poured each liquid into a clear container. Write an explanation which differentiates the difference between each liquid of how and why they layered that way including the relationship of density to the location of each liquid.

7. In terms of density, differentiate between an object which floats in water and an object which sinks in water

8. Density of plain water is 1g/ml. What is the volume of a sample of water if the mass is 6.7g? Explain why this is so easy to figure out.

9. Show how one would set up a ratio to determine the mass of a substance with a density of 5.6g/mL and a volume of 3.7 mL. Then determine the mass.

10. Show how one would set up a ratio to determine the volume of a substance with a density of 2.6 g/mL and a mass of 5.5 g. Then determine the volume.

11. Based on the results of this lab, design an experiment demonstrating how unknown substances can be distinguished from one another by using their densities.

Home Learning:

Students will complete the Analysis Questions.

Extensions:

1. Have students explore the density of objects with identical volumes, but different masses (use density cubes). Discover the relationship among mass, volume, and density.

2. Have students explore the density of different liquids and/or solutions, e.g. 5%, 10%, 15% saltwater solution. Discover the relationship between density and the solute concentration.

Literature Connection:

“Archimedes and the King’s Crown”

An ancient story tells about a Greek king, a gold crown and an amazing scientist named Archimedes. The king had ordered a solid golden crown made. When the court goldsmiths presented it to him, he asked Archimedes to test it to make sure it was pure gold. Archimedes knew that pure gold was very soft. He could bite a piece of it, and his teeth would leave a dent in it. (But he also knew that the king would be mad if he returned a dented crown. He couldn't use THAT test.) Archimedes also knew that if he took equal volumes of gold and water, the gold would weigh 23 times more than the water. He COULD use this test. (The problem was measuring the volume of the crown, an irregular object.).

One night, while filling his tub, for a bath, Archimedes accidentally filled it to the very top. As he stepped into it, water spilled out over the top. The idea struck him, that if he collected the water, and measured it, he would know the volume of his body. HE COULD USE THIS TO MEASURE THE CROWN! In other words, the amount of displaced water in the bathtub was the same amount as the volume of his body.

Archimedes was so excited that he jumped out of the tub. He ran outside and down the street yelling "Eureka! Eureka! (One of the few Greek words I know!) I found the answer!"

www.sciencenet.org.uk/.../Chemistry/ StructBond/c00195b.html

All this was fine except in his excitement, Archimedes had forgotten to put on his clothes.

He was running down the street naked! Archimedes was able to get the volume of the crown and an equal volume of pure gold obtained, no doubt, from the King’s treasury. When he placed the two items into separate pans on a two-pan balance, well, I guess you can figure out the answer if I tell you that the goldsmith was put into jail!

DIFFERENTIATED INSTRUCTION: OPEN INQUIRY

mass, volume, density

Objectives/Purpose:

· Determine the physical properties of liquids.

· Demonstrate that regardless of the size of a sample, the density of a substance will always remain the same.

· Classify and compare substances on the basis of characteristic physical properties that can be demonstrated or measured

Demonstrate Achievement of the following Goals:

· Develop a problem statement based on the density of liquids that you would like to investigate.

· State your hypothesis.

· Design an experiment to test your hypothesis.

· Carry out the experiment you designed.

· Submit a completed lab report to your teacher.

· Use the “Claim, Evidence & Reasoning” rubric to defend your claims when writing your conclusion.

Precipitating Bubbles

Review of the Scientific Method

Florida Next Generation Sunshine State Standards Benchmark(s):

SC.8.N.1.1 Define a problem from the eighth grade curriculum using appropriate reference materials to support scientific understanding, plan and carry out scientific investigations of various types, such as systematic observations or experiments, identify variables, collect and organize data, interpret data in charts, tables, and graphics, analyze information, make predictions, and defend conclusions. (AA)

SC.8.P.8.5 Recognize that there are a finite number of elements and that their atoms combine in a multitude of ways to produce compounds that make up all of the living and nonliving things that we encounter. (AA) (Also assesses SC.8.P.8.1, SC.8.P.8.6, SC.8.P.8.7, SC.8.P.8.8, and SC.8.P.8.9.)

SC.8.P.9.2 Differentiate between physical changes and chemical changes. (AA) (Also assesses SC.8.P.9.1 and SC.8.P.9.3.)

Background Information:

(Reprinted from The Brain in Space: A Teacher’s Guide with Activities for Neuroscience, NASA, URL: http://science.nasa.gov/headlines/y2002/images/playingcatch/spacebrain.pdf)

Scientists aim to gain knowledge and reach an understanding of the world around them. To achieve this goal, scientists must be curious, make observations, ask questions, and try to solve problems. Early scientists tended to draw conclusions from observations that were largely speculative (e.g., that the Earth was flat or that the Sun circled the Earth). By the mid-sixteenth century, some scientists began to realize that using a systematic approach to obtaining information and solving problems could obtain far more knowledge. This resulted in a process which we call the Scientific Method.

Steps of a Scientific Method involving an experimental design

· Identify the problem.

· Collect information about the problem.

· Propose a hypothesis.

· Test the hypothesis by conducting experiments, making comparative observations, and collecting data.

· Evaluate the data collected through investigation.

· Draw conclusions based on data and determine whether to accept or reject the hypothesis.

· Communicate results and ask new questions.

The problem is a statement of the question to be investigated. Observations and curiosity help to define exactly what problem should be investigated and what question(s) answered. Once a problem is defined, a scientist should collect as much information as possible about it by searching journals, books, and electronic information sources. This information will provide a basis for forming the hypothesis.

A hypothesis is often considered to be an “educated guess.” The word “guess” is inappropriate, however, because a hypothesis should be based on information gathered. A hypothesis can be defined more accurately as a “proposed” answer to the problem, based upon background information either gathered through research or through experience. The hypothesis is then tested through experimentation and observation. The results of experimentation provide evidence that may or may not support the hypothesis.

To be effective, experiments must be properly planned. The plan is called the procedure, which describes the things that actually will be done to perform the investigation. This is where decisions are made about which variables will be tested and which will be kept constant, what to use as a control, how many samples to use, how large the sample sizes should be, safety precautions needed, and how many times to run the experiment.

Many scientists investigate questions that cannot be answered directly through controlled experiments in laboratories. For example, scientists studying global warming, the AIDS epidemic, and losses of biodiversity must use comparative methods to examine differences that occur in the natural world.

When developing the procedure for an experiment, consider the following:

1. Test only one variable at a time.

A scientist wanting to find out “why trees shed their leaves in the fall” would have to consider the factors that affect trees, such as the type of tree, the amount of water they receive, the temperature, the length of daylight to which they are exposed, and the type of soil in which they are growing. These are the variables which can cause changes to occur in an experiment.

To obtain reliable results, only one variable should be tested at a time. All others should be kept constant, whenever possible. If the scientist’s hypothesis states that shorter daylight hours cause trees to shed their leaves in the fall, trees of the same age should be tested. They should be placed in the same size pots with the same type of soil, given the same amount of water, and kept at the same temperature. The only thing changed should be the number of hours of light to which different groups of trees are exposed. Any variable that the experimenter chooses to change, such as the hours exposed to light, is referred to as the test variable (independent variable). The change in the experiment that happens as a result of the test variable, such as the length of time that it takes for the leaves to fall, is referred to as the outcome variable (dependent variable).

2. Use controls.

The control is used for comparing the changes that occur when the variables are tested. If a number of young oak trees are placed in a greenhouse and exposed to 10 hours of light to simulate fall conditions, how will the scientist know if a loss of leaves is due to the amount of light? It could be due to the temperature that he/she chose or the amount of carbon dioxide in the air. To avoid such uncertainty, two identical experiments must be set up: one in which the trees are exposed to 10 hours of light and the other, the control, in which they are exposed to light for a longer period of time to simulate summer conditions. All factors for the control are exactly the same as for the test except for the variable being tested—the amount of light given to each tree.

3. Use several samples.

Using a number of samples prevents errors due to differences among individuals being tested. Some trees are heartier than others. If only a few trees are tested, some may lose leaves for reasons that are not related to the amount of light. This will produce misleading results. Larger numbers of samples will provide more accurate results.

4. Always use appropriate safety measures.

Safety measures to be followed vary according to the type of experiment being performed. For example, laboratory-based experiments frequently require that participants wear protective clothing and safety goggles and that dangerous volatile chemicals be used only under a vented fume hood.

5. Repeat the experiment several times.

To make valid conclusions, the scientist must have reproducible results. Ideally, comparable results should be obtained every time the experiment is run.

After the plan or procedure is complete, the experiment is run. It is essential that careful and accurate records be kept of all observations during an experiment. The recorded observations and the measurement comprise the data. It is always useful to present data in the form of charts, tables, or graphs, as these provide a visual way to analyze and interpret the results. When drawing graphs, the test variable (independent variable) is conventionally plotted on the horizontal axis, and the outcome variable (dependent variable) is plotted on the vertical axis. Analysis of data from the experiment allows the scientist to reach a conclusion. The scientist determines whether or not the data support the hypothesis and decides whether to accept or reject the hypothesis.

The conclusion should provide an answer to the question asked in the problem. Even if the hypothesis is rejected, much information has been gained by performing the experiment. This information can be used to help develop a new hypothesis if the results repeatedly show that the original hypothesis is inappropriate. After performing many investigations on a particular problem over a period of time, a scientist may come up with an explanation for the problem, based on all the observations and conclusions made. This is called a theory.

A Scientific Theory is an explanation, supported by data, of how or why some event took place in nature.

MAJOR CONCEPTS for the Teacher

· Our exhaled breath contains carbon dioxide gas.

· The carbon dioxide we exhale reacts with calcium hydroxide in solution to form insoluble calcium carbonate and water.*

· Formation of calcium carbonate precipitate can be used as a test for the presence of carbon dioxide.

· If carbon dioxide continues to be bubbled into limewater (calcium hydroxide solution) after a period of time, the white precipitate disappears. The excess carbon dioxide forms carbonic acid in the water and the calcium carbonate reacts with the