# Matter - Density - Science Processes & Inquiry (middle grades) Activity and Lesson plans

## Overview

The main idea associated with these activities is density. Density, as it is developed within these activities threads most closely to two standards: matter and measurement. Density being a property of matter, a relationship between two other properties of matter, mass and volume. Concepts of mass, volume, measurement of mass and volume, the idea of thinking about matter as composed of small particles, and science processes how to use properties, variables, experimental evidence, reasoning, explanations, operational definitions, and conclusions.
These ideas are further defined and clarified beginning with the following curriculum mapping.

## Big ideas, concepts, facts, and outcomes

### Physical science - matter

Big ideas: All objects are made of matter - Matter takes up space, has mass, and exist in different states (solid, liquid, gas, and plasma).

### Related concepts and facts

• Elements - the smallest particles that compose everything in the universe. Determined by the number of protons.
• Properties of matter change at different rates.
• Mass is the amount of matter in an object.
• Volume is the space an object occupies.
• Density is the relationship of mass and volume.
• Density of water is 1g/ml.
• Density can be used to describe population for a particular area.
• Certain materials sink and certain materials float.
• An object will float if it displaces (pushes away) a mass of liquid less than or equal to its mass.
• The shape of an object will affect if it sinks or floats. The greater the surface area of the object, the more likely it will float. The greater the surface area (Surface area is the area of the outer part or upper most part of a two-dimensional or three-dimensional object.) that rests on the water the better the water will hold up the material because the water can exert a greater force (buoyancy).
• Buoyancy is the force exerted by a liquid on an object in the liquid. It depends only on the volume of the object and not on the mass of the object in the liquid.

### Outcome

Matter - Describe the mass, volume, and structure of matter as determined by atoms and molecules.

### Specific outcomes

• Describe matter as having mass and volume. (3)
• Describe matter as composed of atoms. (6, 8)
• Describe atoms as too small to see. (6)
• Describe arrangements of particles in physical states of matter (solid, liquid, gas). (3)

Density

• Uses variables mass and volume to explain floating.
• Density can be used to explain sinking and floating.
• Describe the relationship of mass and volume as it relates to density. (8)
• Describe density as a result of the structure of matter in terms mass and volume.
• Predict the relative density of various solids and liquids (based on observations). (5)
• Calculate the density of different solids, liquids, and gas. (6)

### Unified Process - Properties Constancy, Change, & Measurement

Big ideas: Properties of objects are determined by the elements from which they are made. Properties can remain constant, change, and be measured. They are used to identify objects, as variables in experiments, operational definitions, and explanations. Properties of matter include: color, texture, size, shape, mass, volume, density, temperature, chemical, energy, states of matter (solid, liquid, gas, plasma) and the ability to interact with other objects. Properties can be measured with scientific tools and compared to a standard unit (linear, time, temperature, mass, volume, and density)

### Related concepts and facts

Properties

• Properties are used to identify objects, elements, matter...
• Properties are characteristics of an object.
• Properties include: color, texture, size, shape, mass, volume, density, temperature, chemical, energy, and the ability to interact with other objects.
• Properties can be used to compare objects. (1)
• Properties of matter can be measured using tools such as rulers, balances, graduated cylinder, displacement, and thermometers. (4)
• Some properties of objects change and some properties don't change.
• Properties and change of properties can be quantified.
• Objects, properties, and events stay the same or change in similar ways.
• Properties are used to define all objects.
• Definitions include properties.
• Definitions can be changed by changing properties.
• Properties can usually be varied and used as variables to investigate with reasoning.
• Variables can be identified and described as to how they change or don't change.

Change can be quantified. Change can be related to variables. Variables can be used to describe change. Evidence for interactions and subsequent change and the formulation of scientific explanations are often clarified through quantitative distinctions by measurement.

• Change can be related to variables.
• Variables can be used to describe change.
• Operational definition - describes how the variables operate or change.

Measurement: properties can be measured with scientific tools and compared to a standard unit (linear, time, temperature, mass, volume, and density).

• Properties can be measured using tools such as rulers, balances, and thermometers.
• Measurement helps in make more accurate and better observation.
• All measurement is relative to a unit, usually a standard unit.
• A standard unit of measurement helps communication.
• Quantitative estimates of familiar lengths, areas, volume, mass, weigh, and time intervals can be confirmed by measurement.
• Length measures distance, linear measurement. It is measured as a line with a ruler. Common standard units of length include: mm, cm, m, km, foot, yard, mile. The standard metric unit of length is the meter.
• Volume is the measurement of space an object occupies. It is measured with measuring cups and graduated cylinders. Common units of volume include: ml, l, cup, pint, quart, gallon. The standard metric unit of volume is the liter. Operational definitions for measuring volume:
1. Volume can be measured directly for liquids in a measuring cup or graduated cylinder.
2. Volume can be measured by water displacement particularly for irregularly shaped objects.
3. Volume can be calculated as a product of linear measurements, l * w * h for cubic or rectangular shapes.
4. Volume can be calculated from area and linear measurements.
• Area measures the surface of an object. Common standard units of area are hecter, acre, and square measures of: cm, m, km, ft. yd. mi.
• Mass is the measure of how much matter is in a particular object or particular space. It is measured with balance scales (triple beam balance). Common units of mass include: g, kg, pounds, ounces, tons. The metric unit of measurement is the gram.
• One gram is about the same mass as a large paper clip.
• A milliliter of water has the same volume as one cubic centimeter of water.
• Measurement as a system gets more complicated so gain understanding by using summaries: average, range, to describe the relative properties of the system.
• All measurement has error.
• Scale is a proportional relationship of characteristics, properties, or relationships within a system as its dimensions are increased or decreased.
• Scale includes understanding that different characteristics, properties, or relationships within a system might change as its dimensions are increased or decreased.
• Rate involves a measure of change for a part relative to a whole (birth rate as part of population growth and comparing one measured quantity to another measured quantity (km per hour).
• Rate involves comparing one measured quantity with another measure quantity (50 meters per second). Rate is also a measure of change for a part relative to the whole, (birth rate as part of population growth).

### Outcome

Uses properties to identify objects, describe characteristics of an object, variables in experiments, cause and effect, and make explanations.

### Specific outcomes

• Describe properties as characteristics of an object.
• Use properties to identify and describe objects.
• Use properties to identify variables, create experiments, operational definitions, and explanations.
• Accurately measure the properties of matter in different states.
• Select and use appropriate instruments to measure mass and volume of solids and liquids and record the data. (6)
• Describe procedures to measure mass and volume of solids, liquids, and gases. (3)

### Science investigation / inquiry / experiment

Big Ideas: Science investigation, inquiry, & experiment use observation to answer questions. Observation that can be observed repeatedly to build confidence in understanding by connecting reasoning for why certain observations occur.

### Related concepts and facts

• Variables are conditions that change and can be measured.
• Variables can be identified and used to suggest causes and reasons for change.
• Explanation relates one variable to another? The greater the surface area the greater the buoyancy.
• Operational definition describes how one variable operates on another. The change in surface area changes how an object sinks or floats?

### Outcome

• Focus on variables relationship to understanding and the creation of hypothesis, investigations, operational definitions, and explanations.
• Uses properties to identify objects, describe characteristics of an object, variables in experiments, cause and effect, and make explanations.

### Specific outcomes

• Identify properties
• Recognize variables as properties that can change.
• Describe how to reason about variables.
• Describe how variables are used to focus an investigation. (6)
• Describe how variables are used in making hypothesis, operational definitions, and explanations.

# Pedagogical Overview & Teacher plans

Activities are designed and sequenced to provide the power of a Learning Cycle.

Use the Science Assessment DataBase to select assessment questions for the science standard categories desired to create a diagnostic assessment (pretest).

1. Explain to students the assessment is to help understand what they know and don’t know in the particular science categories and the results will NOT be used for student’s grade.
2. Provide a copy of an assessment to each student.
3. Have them complete it and check their answers.
4. Let students set goals for their coming investigations.

## Activities Sequence to provide sufficient opportunities for students to achieve the targeted outcomes.

Prior knowledge of measurement of: linear, mass, volume, matter, and investigation is helpful as these activities will review these ideas, but not introduce them.

## Focus question

Unit focus question:

What causes objects to sink and float?

### Sub focus questions:

1. How does shape affect if an object sinks or floats?
2. How does mass affect if an object sinks or floats?
3. How does volume affect if an object sinks or floats?
4. What is density?
5. What is buoyancy?

## Scoring guides suggestions (rubric)

### (scoring guide)

Top level

• Describes density as a proportional relationship of mass and volume.
• Described density as a relationship of mass and volume (not proportional).
• Completed lab sheet. Says mass and volume relates to density, (not how relates).
• Parts of the worksheet are not complete. Mentions mass, volume, and density (no mention of them being related).

Lower level

Top level

Lower level

## Lesson Plans

### Activity 1 - Do Diet Pop / Non Diet Pop Cans Float or Sink?

Materials:

• One unopened can of the same brand and flavor of regular pop and diet pop. May also add caffeine free pop and others if available.
• Container of water large enough to float or sink them.
• Other instruments as students request them - balance, over flow collector, calculator, ...

Concepts:

Focus questions:

1. What causes an object to sink or float?
2. What varables affect if the cans sink or float?

Learning outcomes:

1. Identify mass and volume as properties of matter.
2. Identify mass and volume related to density.
3. Use observations to predict the relative density of various solids and liquids.
4. Identify different kinds of (liquids) matter are in different kinds of pop.
5. Identify properties that effect change as variables. Possible variables for the pop can differences are mass, weight, or density.
6. Identify properties that can be used as variables to operationalize how the observations occur.
7. Suggest explanations for cause and effect of variables and how they could cause the difference.
8. Use properties as variables to explain observations.
9. Use reasoning and explanations for cause and effect by discussing variables and how they could cause differences.

Scoring guide

Top level

• Accept anything that identifies a variable related to density and a logical explanation.

Lower level

Suggested procedures overview:

Concepts:

Prior knowledge

• Certain materials sink and certain materials float.
• Cause effect relationship, identification of variables, properties of matter, solution, use of models for explanations.
• Different kinds of matter have different properties, mass, volume.

Procedure

Exploration

1. Ask the students what will happen when each can is placed in the container of water?
2. Why do you think they will or won’t float?
3. What might explain why each sinks or floats?
4. How can we use science processes?
5. How does inquiry support our reasoning?

Invention - Formative

1. Collect data, Record data, Share data

Summative

If they mention both variables of mass and weight that is good for starting. The relationship between the two will come with further exploration. If they mention the word density ask them to explain what they mean by it. Ask them if they could define the variables related to the idea of density and how they operate to make and change density.

Introduce the idea that Nutra-sweet is 1000 times sweeter than sugar and ask how that might effect what is going on. If they mention density ask how they can figure out the density of each can (using water displacement and mass...) If they focus only on mass, that’s okay. Suggest it is a variable and if effects whether things sink or float. You may or may not want to suggest there is more to understand.

Work sheet:

Name _______________

Lab notes - Do Diet Pop / Non Diet Pop Cans Float or Sink?

Write and draw what you saw for the diet pop

Write and draw what you saw for the non diet pop

Data:
Pop
Diet
Non diet

Analysis:
What variables do you think might effect a difference?

What causes you to believe one of those variables could cause a difference?

Conclusions

### Activity 2 - Floating and Sinking Potatoes

Materials:

• Potatoes, knife,
• container A with one liter fresh water
• container B with one liter of salt water. Salty enough to float potato pieces or whole potato,
• container C to create a mixture of ¼ liter of salt water and ¼ liter of fresh water.

Concepts:

Focus questions:

1. What causes objects to sink and float?
2. Will objects sink and float in different liquids?
3. How do we explain the results?

Learning outcomes:

1. Identify mass and volume as properties of matter.
2. Identify mass and volume related to density.
3. Use observations to predict the relative density of various solids and liquids.
4. Identify different kinds of (liquids) matter are in different kinds of pop.
5. Identify properties that effect change as variables. Possible variables for the pop can differences are mass, weight, or density.
6. Identify properties that can be used as variables to operationalize how the observations occur.
7. Suggest explanations for cause and effect of variables and how they could cause the difference.
8. Use properties as variables to explain observations.
9. Use reasoning and explanations for cause and effect by discussing variables and how they could cause differences.

Scoring guide

Top level

• Identify variables (mass of the water solution and mass of the potato) that affects sinking and floating potatoes.
Apply the idea or model of solutions (a mixture where a substance (solute) is uniformly distributed within another substance (solvent) to an explanation as to why the potato floats or doesn’t float in fresh and salt water.
• Accept anything that identifies a variable related to density and a logical explanation.
• Focuses on weight as variable that affects if the potato floats or sinks.

Lower level

Suggested procedures overview:

Concepts:

Prior knowledge

• Liquids can have different mass (weight).
• Cause effect relationship, identification of variables, properties of matter, solution, use of models for explanations.
• Different kinds of matter have different properties, mass, volume.

Procedure

Exploration

1. Don’t tell the students what is in either container.
2. Ask. What will happen when potato pieces are put into container A and B?
3. Have students write their prediction of what is going to happen and their explanation of what variables they think will determine or cause it. (Potato and solution volume, mass, density).
4. Insert different sizes of potato pieces in each container.

Invention

1. Collect data, Record data, Share data.
2. If students haven't suggested the liquid in each container is different, then suggest it as a possibility.
3. Have the students write one or more sentences describing what they think is happening differently according to different variablesd. (size of potato, purity of the water, …)
4. Again if students use the word “Density” ask them to define it operationally (explain what variables are affecting it and how are they doing it. How does the purity of the water, water, the mixed water, and the salty water operate on the potato? The salt is lifting it and the more salt the greater the lift (buoyancy).

Formative

1. Pour 250 ml of salt water into the third container (C), slowly pour 250 ml of fresh water on top as if it would float on top of the salty water, and label it C
2. Ask.Predict what will happen when potato pieces are inserted.
3. Insert potatoes.
4. Collect data, Record data, Share data
5. Discuss
Work sheet:

Name _______________

Lab notes - Floating and Sinking Potatoes in Water

Write and draw what you saw for the potato in container A.

Write and draw what you saw for the the potato in container B.

Write and draw what you saw for the the potato in container C.

Analysis:
What variable do you think made a difference?

What causes you to believe that variable could cause a difference (size of potato, kind of liquid, ... )? How does the variable operate on the potato as it changes?

What do you believe a potato will do in these kinds of water:
Regular water

Semi salty

Mostly salty

Explanation or relationship?

Conclusions

### Activity 3 - Floating and Sinking Clay (Boats)

Materials:

Clay, containers of water, towels, balances to mass clay, lab notes

Concepts:

Focus questions:

1. Can the same material both sink and float in the same liquid?
2. What property or properties would need to change to achieve this?

Learning outcomes:

1. Identify mass and volume as properties of matter.
2. Identify mass and volume related to density.
3. Use observations to predict the relative density of various solids and liquids.
4. Identify different kinds of (liquids) matter are in different kinds of pop.
5. Identify properties that effect change as variables. Possible variables for the pop can differences are mass, weight, or density.
6. Identify properties that can be used as variables to operationalize how the observations occur.
7. Suggest explanations for cause and effect of variables and how they could cause the difference.
8. Use properties as variables to explain observations.
9. Use reasoning and explanations for cause and effect by discussing variables and how they could cause differences.

Scoring guide

Top level

• Identify variables (mass of the water solution and mass of the potato) that affects sinking and floating potatoes.
Apply the idea or model of solutions (a mixture where a substance (solute) is uniformly distributed within another substance (solvent) to an explanation as to why the potato floats or doesn’t float in fresh and salt water.
• Accept anything that identifies a variable related to density and a logical explanation.
• Focuses on weight as variable that affects if the potato floats or sinks.

Lower level

Suggested procedures overview:

Concepts:

Prior knowledge

• The shape of an objects affects if it sinks or floats.
• Cause effect relationship, identification of variables, properties of matter, solution, use of models for explanations.
• Different kinds of matter have different properties, mass, volume.

Procedure

Exploration

1. Ask. What will happen if a clay ball is dropped into water.
2. Ask. Is there a way to make the clay float?
3. Tell. Divide the clay into two lumps. Challenge to make two shapes: one that sinks and one that floats.
4. Decide when to share ... Hint ... The greater the surface area covered by the material, the more likely it will float, because there is more water pushing up on it or the object is spread out over more water so there is less weight above the surface area the water has to support.
5. Have students write in their lab books what they think makes objects sink & float.
6. Have them create their shapes, draw a picture, test them in the water, and explain why they think it sunk or floated.

Invention

1. Have students share their data and describe what they learned.
2. Make a class chart with pictures of floaters and sinkers.
3. Categorize shapes of clay that sunk and shapes of clay that floated.
4. Ask. What each group has in common?
5. How do you think shape makes a difference?
6. Ask. How to change the clay sinkers so they would float?
7. Ask. How to change the clay floaters so they would sink?
8. What names do scientist give this list of things (variables)?
9. Use a drawing as a bridge to demonstrate forces of water and mass of the clay for examples that would float and sink.

Formative

1. Ask what advice would give a person that makes ships out of steel?
2. Ask. How do ships float?
3. Describe characteristics of the designs that caused them to float or sink.
4. Did you identify a variable and how it changes.
5. Did you describe a hypothesis that relates one variable to another? (The greater the surface area the greater the buoyancy.)
6. Or did you write an operational definition to describe how one variable operates on another? (The change in surface area changes how an object sinks or floats?
Work sheet:

Name _______________

Lab notes - Sink and Float - Clay Boats

Write and draw your understanding of sink.

Write and draw your understanding of float.

Procedures:

1. Take a clay ball.
2. Divide it into two equal pieces.
3. How do you know they are equal?
4. Make two shapes: one that sinks and one that floats.
5. Below, draw a picture of each.
6. Test them in the water.
7. Explain why they sunk or floated.

Data:

Draw each shape and label if they sunk or floated.

Analysis:
What variable do you think made a difference?

What causes you to believe that variable could cause a difference?
How does the variable operate on the clay as it changes?

Operational definition, or relationship?

Conclusions

### Activity 4 - Different Sizes of Cups & Pennies - Buoyancy

Materials:

Styrofoam cup, containers of water, towels, balances to mass pennies, boats, and water, science lab book

Concepts:

Focus questions:

1. Can the same material both sink and float in the same liquid?
2. What property or properties would need to change to achieve this?

Learning outcomes:

1. Add pennies to styrofoam cups of different sizes and record how the increase of mass displaces an increased mass of water.
2. Explain that the greater the mass in the cups the greater the mass of the water displaced.
3. Explain that the styrofoam boat floated as long as there was an equal mass of water to be displaced. If there is an equal force of water pushing up on it, then it will float.
4. Explain a variable is a property that changes.
5. Explain how variables can be used to describe how something operates (operational definition).
6. Use reasoning and explanations for cause and effect by discussing variables and how they could cause differences.

Scoring guide

Top level

• Identify variables (mass of the water solution and mass of the potato) that affects sinking and floating potatoes.
Apply the idea or model of solutions (a mixture where a substance (solute) is uniformly distributed within another substance (solvent) to an explanation as to why the potato floats or doesn’t float in fresh and salt water.
• Accept anything that identifies a variable related to density and a logical explanation.
• Focuses on weight as variable that affects if the potato floats or sinks.

Lower level

Suggested procedures overview:

Prior knowledge

Concepts:

• The volume of an object will affect when it sinks or floats.
• The greater the surface area that rests on the water the better the water will hold up the material (the liquid (water) exerts more pressure (greater force, buoyancy) on a larger surface (area).
• Cause effect relationship, identification of variables, properties of matter, solution, use of models for explanations.
• Different kinds of matter have different properties, mass, volume.

Procedure

Exploration

1. Ask. What will happen if a styrofoam cup is put into water?
2. Ask. What will happen as pennies are added to the cup?
3. How will the size of the cup affect how many pennies can be added to it before it sinks?
4. Have a grand conversation about how to conduct an investigation to answer the question. Or just give students the challenge and let them begin and see what happens.
• Challenge: Make styrofoam boats that are ¼ of a cup, ½ of a cup, ¾ of a cup, and 1 cup, float each, add pennies until they sink, and record the information.
• Possible variable information to record. Mass of pennies, number of pennies, volume of cup, volume of container, volume of displaced water, mass of displaced water.
5. Tell students to create their boats (shapes), draw a picture, test them in the water, write in your lab notes what happened to the styrofoam boat as pennies were added, what happened when the styrofoam cups floated, and when they sunk.

Invention

1. Data students collected may or may not be sufficient to answer the following question. It not, then have students collect the missing information as the need arises.
2. Ask. How does the size of the cup affect when each cup sunk (number of pennies added before the cup sinks).
3. Make a class summary chart for the size of boats and the number of pennies each held when sank.
4. Discuss the relationships between pennies mass, change in water, cup volume, other ...
5. Ask. Do you know the volume of water each cup holds? (measure with graduated cylinder).
7. If they don't mention it raises the height in the water container, demonstrate to show displacement.
8. Ask. How they can find the volume and mass of the displaced water? (measure by lowering cup into full container of water and collecting the over flow and measure it in a graduated cylinder and scale).
9. Ask. What the surface area of each cup is?
Ask. What each group has in common for each cup?
How do you think shape makes a difference?
10. Use a drawing as a bridge to demonstrate forces of water and mass of the boat (pennies) and the mass of the displaced water as the pennies are added.

Summative Evaluation

1. Draw a picture of a cup that has the amount of pennies that sunk it.
Draw and label the amount of water that it displaced when it was floating, just before it sunk.
2. Draw the cup in water without the pennies. Draw and label it just before it sunk.
3. What variables were included in the drawing?
4. Did the drawing show the relationship between the number of pennies and amount of water displaced?
5. Did students collect measurable evidence of /for variables?
6. Were the variables mass of pennies, displaced water mass, or volume of displaced water?
7. As a conclusion did students include variables and describe how they operated?
8. Is there data to support
• How shape made a difference?
• How mass of the pennies related to the mass of displaced water?

Formative

1. Ask. What advice would give a person that makes decisions about the amount of ballast a ship needs to balance its load?
2. Describe characteristics to use to decide how to achieve the optimum amount of balast to minimize a boat from capsizing.
3. Did you identify a variable and how it changes.
4. Did you describe a explanation that relates one variable to another? (The mass in the ship (load + ballast) must float the ship so the water level is appropriate (the ship sits in the water so it isn't too low (sink) or to high (capsize).
5. Or did you write an operational definition to describe how one variable operates on another? (The change in load + ballast changes how low or high the boat floats in the water).
Work sheet:

Name _______________

Lab notes - Different Sizes of Cups & Pennies - Buoyancy

Write and draw your understanding of buoyancy

Procedures:

Cup Data

• Quarter cup
• Half cup
• Three-quarters cup
• Whole cup

Analysis:

What variables were measured?

When variables are measured that implies they are measured to describe change.

What variables changed (manipulated & responding)?

How do you think the changes made a difference?

What causes you to believe each variable could cause a change?

Describe how the variables operate on the cup as it changes?

Explanation or Operational definition?

Conclusions

### Activity 5 - Measuring Mass & Volume

Materials:

• Balances, graduated cylinders, containers, rulers, overflow cups (optional)
• Objects to measure wooden blocks, clay pieces, liquids, marbles, glass spheres, (May want to have a group of materials for students so there is something in common to discuss and share. May also want to have two objects that are different sizes, but made from the same material.)

Concepts:

Focus questions:

1. What is the difference between mass and volume?
• Mass is the amount of matter in an object.
• Volume is the amount of space an object occupies.
2. How do you measure mass?
3. How do you measure volume?

Learning outcomes:

1. Describe operational definitions for measuring mass and volume.
2. Measure mass and volume of common objects.

Scoring guide

Top level

• Describe mass & volume and different ways to measure them with standard units of measurement (metric and American).
• Know mass and volume are units of meaasurement.

Lower level

Suggested procedures overview:

Prior knowledge

Concepts:

• Volume is the measurement of space an object occupies. It is measured with measuring cups and graduated cylinders. Common units of volume include: ml, l, cup, pint, quart, gallon. The standard metric unit of volume is the liter. Operational definitions for measuring volume:
1. Volume can be measured directly for liquids in a measuring cup or graduated cylinder.
2. Volume can be measured by water displacement particularly for irregularly shaped objects.
3. Volume can be calculated as a product of linear measurements, l * w * h for cubic or rectangular shapes.
4. Volume can be calculated from area and linear measurements.
• Mass is the measure of how much matter is in a particular object or particular space. It is measured with balance scales (triple beam balance). Common units of mass include: g, kg, pounds, ounces, tons. The metric unit of measurement is the gram.

Procedure

Exploration

1. Focus the students by holding up 3 different shapes of 1 liter (or larger equal size) containers.
2. Ask. Do these hold the same amount or have the same volume?
3. Ask. How would you order them according to the volume of water the containers would hold?
4. Have a student fill one of the containers with water and demonstrate by pouring the water from it to a a measuring cup or graduated cylinder to see if the volumes are the same (or not).
5. Continue pouring from one flask to the other until they have all been compared.
6. Ask. Can you suggest three ways to measure volume?
1. Volume can be calculated as a product of l * w * h for cubic or rectangular shapes,
2. Volume can be measured by water displacement particularly for irregularly shaped objects.
3. Volume can be measured directly for liquids in a graduated cylinder or measuring cup.

Invention

1. Tell that each method or procedure is an operational definition for measuring volume.
2. Ask. What is an operational definition for measuring mass? (Mass is measured by comparing an known mass to an unknown mass. Such as putting an unknown mass on a balance or triple beam to compare them by balancing them.)
3. Have a student demonstrate a few examples.

Formative

1. Show students an object.
2. Ask. What would you estimate as its mass and volume?
3. Make several more measurements of different objects. (Include solids and liquids in different containers)
4. Record them.
5. Write the results on the board for each object and compare their findings.
6. Ask. Is there a relationship to an objects mass and volume. ... Don’t push the idea of calculating density unless students suggest it. Opportunities will come in later activities.
Work sheet:

Name _______________

Lab notes - Measuring Mass and Volume

Write and draw your understanding of mass

Write and draw your understanding of volume

Procedures:
Find the masses of several objects using the triple beam balance. (Remember - If the substance is in a container, you must subtract the mass of the container from the mass of the substance and the container.)

Object Mass

Find the volume of several objects. Decide with your group which method of finding volume will be used. (operational definition)

Object Volume

Describe with your group different methods to measure volume.

Record the volume and mass of the different objects below.

1. Object .................. Volume ............ Mass .......... Method of finding

Analysis:

How did your results compare to others?

If there are differences what should be done?

Which way of measuring volume seems most accurate?

Why?

What is the relationship between a cubic centimeter and a milliliter?

What is a way you can remember what mass is?

What is a way you can remember what volume is?

### Activity 6 - Measuring Metal Cubes: mass, volume, & density

Materials:

• Density block sets, aluminum, steel, brass, copper, lead, iron. (they are the same size and volume) or other set of objects if blocks aren't available, metric ruler, triple beam balances, calculator, worksheet

Concepts:

Focus questions:

1. If mass and volume can't be used to predict if objects sink or float, how can they be used to measure a property that can?

Learning outcomes:

1. Measure mass and volume and use it to explain density.

Scoring guide

Top level

• Student data for mass, volume, and density should be in the ball park with appropriate unit labels.
• Understand density as related to mass and volume, but not necessarily as a proportion or ratio between them.

Lower level

Suggested procedures overview:

Prior knowledge

Concepts:

Procedure

Exploration

1. Ask. How can we find the mass and volume of each cube.
2. If necessary, review procedures for finding mass and volume.
3. Discuss concept of density as the relationship of mass to volume and visual of cylinder with cotton balls, smashed or spread out.
4. Find the mass and volume or each cube and record the data.
5. Are mass and volume properties? yes
6. Are mass and volume variables? yes/no - Aren’t for each object, but are when comparing one object to another.
7. Are they properties of matter?
8. Can you use your data to calculate density?
If need be, have the students review their notes on matter.

Invention

1. Have students collect measurements to find the density of the four different metal cubes.
2. Share the data with the class
3. Discuss results.
4. Why are the measurements different and the same?
5. Why are the densities different?
6. What does density measn?
7. What does it mean to compare 2 variables to describe a third variable?
8. How can you use the ideas of particles and atoms to explain the difference?
9. Get students to talk about atoms packed in differently to visualize a model of density.
10. Draw pictures of four different cubes like the sample cylinders with cotton balls.
11. Share pictures of models that show how objects of the same size (volume) can have different densities.

Formative

1. Densities of different materials can be found in engineering and machinists manuals. After students calculate their densities find a reference book and let students compare their calculations.
2. Talk about how different materials are used for different for different puposes. Airplanes, different containers, and how density might be used when selecting materials for different designs.
Lab sheet:

Name _______________

Lab notes -Measuring Metal Cubes: mass, volume, & density

Review: Mass is the amount of matter in an object. Volume is the space the object takes up. Density is the amount of matter (mass) related to the space it occupies (volume).

Imagine the example below as two cylinders filled with cotton balls that have the same mass. One group of cotton balls are smashed and the other are pulled apart. The volume of each cylinder is the same and the mass is different.

If the volume is one liter and the mass is 6 grams and 30 grams, then what is the relationship of mass to volume (density) of each? Look at the different cubes and order them from the least to most dense.

How did you arrange them in order of their densities?

If you could see the particles in the cubes, which would have the most mass per volume?

Which would have the least mass per volume?

Procedures:

Measure and record the mass of each cube.

Measure and record the volume of each cube.

Calculate the density of each cube.

Cube Mass Volume Density = mass / vol.

Analysis

How are the blocks the same?

How are the blocks different?

Label and draw a representation of the particles that make up these cubes.

Why would a scientist or engineer want to use two variables (mass & volume) to create a third (density)?

Which do you think might be used for building airplanes?
Why?

Why do you think that the shiny silver cube is used to make pop cans?

### Activity 7 - Challenge: Changing the Density of Bread

Materials:

Slice of bread, balance, metric ruler, calculator, plastic knife, lab sheet

Concepts:

Focus questions:

1. How can you change the density of a slice of bread?

Learning outcomes:

1. Use ideas related to density to solve problems.
2. Given the tools they will come up with a plan of how to change the density of bread. It might be to squish the bread or toast it.
3. Compute and record the starting mass, volume, and density; plan and conduct an experiment; record the finishing mass, volume, and density; and report the results.

Scoring guide

Top level

• Student data for mass, volume, and density should be in the ball park with appropriate unit labels.
• Understand density as related to mass and volume, but not necessarily as a proportion or ratio between them.

Lower level

Suggested procedures overview:

Prior knowledge

Mass, volume, density, investigative procedures

Concepts:

Procedure

Exploration

1. Show students a slice of bread.
3. How is it determined?
4. How can it be changed?
Should not need to provide much assistance. Students should be good with devising and conducting experiments.
5. Provide students with the materials and let them start.

Invention

1. Ask. How did you change the density?
2. Describe mass, volume, and density as a variable and how they varied from before to after.
3. Draw a model to represent each - before and after - and how each changed or did not change.
4. Write an operational definition that describes the change.
• As the bread is smashed it decreases the volume while the mass remains the same which results in a greater density.
• While the bread is toasted water evaporates decreasing the mass and not the volume. It remains the same (or a tad bit less, but not as less as the mass) resulting in a decrease of density.

Formative

1. How does the density of different materials change when their temperature changes? Like explansion and contraction of bridges, roads ...
2. What do engineers do to allow for expansion and contraction?
Work sheet:

Name _______________

Lab notes - Changing the Density of Bread - Before and After ...

How can you change the density of a slice of bread?

Materials: One slice of bread, balance, metric ruler, calculator, plastic knife.

The density of a slice of bread can be changed by

Procedure:

1. Cut the slice of bread to a square or other convenient shape.
2. Measure and record the following data:

Data:

Before

Mass

Volume

Density

Operational definition:

If the bread is _________________ (what was done to it)

the ____________________ (what variable was changed)

will be _________________ (changed in this way)

This will result in a change of ______________ by

________________ it.

After

Mass

Volume

Density

The density changed because

Can you think of other ways to change the density?

Draw a picture to show the particles in the bread before and after you changed it.

Conclusion: (two things you learned)

### Activity 8 - Challenge: Can You Make an Egg Float?

Materials:

Hard boiled egg, container, water, measuring spoon, 1-2 cups of salt, lab sheet

Concepts:

Focus questions:

1. Do eggs float?
2. How do you make an egg float?

Learning outcomes:

1. Use ideas related to density to solve problems.
2. Manipulating and control variables to solve a problem. The amount of water and salt used to float the egg.
3. Add salt to water to increase the density of the water to effect how an egg floats or doesn’t float.

Scoring guide

Top level

• Completed worksheet. Describes how more salt increased mass or density until there was enough to support (float) the egg.
• Completed worksheet. Described density as a relationship of mass and volume (not proportional).
• Completed worksheet. Says adding more salt caused the egg to float, but not reason as to how.
• Includes amount of water and salt. Mentions salt and water, but not how it changed in a way to float the egg. Or Parts of the worksheet are not complete.

Lower level

Suggested procedures overview:

Prior knowledge

Concepts:

Procedure

Exploration

1. Ask. Do eggs float? no
2. How do you make an egg float?
3. If I suggest you can use salt to make an egg float, how might use salt to float an egg in water? Think how to change density.
4. If students don’t have suggestions, model how to create an experiment by thinking out loud.
5. Allow a lot of wait time before saying the italicized words.
6. If I put an egg into a glass of water, I can see if it floats or sinks. If it doesn’t float it will sink.
7. I might be able to make if float, If I change either the mass or the volume.
8. I can change the mass of the water if we add salt to change the density.
9. If salt is added, that should make the water salt solution more massive or dense.
10. I can add one tablespoon and stir, then I can see what happens and continue to add salt until the egg floats.
11. How should we set it up and conduct it?
12. Suggest: set up, how to conduct it add salt, measure what and when, record data, and possible results.
13. Might suggest to mass the water and salt before and after or if they don’t suggest it, then might want to go ahead and let the logical consequence play out - lack of data - redo or do without.

Invention

1. Ask. How the amount of salt relates to the amount of water?
2. If the investigation was done in groups, then share all the results and discuss why there are differences?

Formative

1. If your younger brother was not a good swimmer, where would you encourage him to swim, in the Great Salt Lake or in a swimming pool? Why?
Work sheet:

Name _______________

Lab notes - Egg Float

Materials: hard boiled egg, container with water, tablespoon, salt, graduated cylinder.

How can you make the boiled egg float?

Procedure:

Decide how you will set up, conduct, and record the data from this investigation.

Data:

How much water did you use?

How much salt did it take to float the egg?

How much did the volume change?

How does the amount of salt compare to the amount of water?

Analysis:

Why does the egg not float to begin with?

Why does the egg float at the end?

Check your answers with others in the room. Why are the amounts of salt different?

Conclusion: (two things you learned)

### Activity 9 - Challenge: Density of Different Kinds of Wood

Materials:

• Wood blocks of different sizes and different types (a wood shop is a great place to find them good samples are oak, pine, ash, balsa, ebony (really need ebony to show not all wood floats) metric ruler, balance beam, worksheet

Concepts:

Focus questions:

1. Does wood float?
2. Do different species of wood float differently?

Learning outcomes:

1. Use ideas related to density to solve problems.
2. Use mass and volume to calculate density and explain different properties of wood.
3. How are different woods used in construction (hard wood, soft wood ..)

Scoring guide

Top level

• Student data for mass, volume, and density should be in the ball park with appropriate unit labels.
• Understand density as related to mass and volume, but not necessarily as a proportion or ratio between them.

Lower level

Suggested procedures overview:

Prior knowledge

Concepts:

Procedure

Exploration

2. Ask. Do different species of wood float differently?
3. How does density affect the use of wood in construction and other uses?
4. Decide how to measure mass & volume and calculate density.
5. Decide on what accuracy is appropriate (round to tenths).
6. Collect and record information.

Invention

1. Share data and compare densities.
2. Ask. How are they the same and how are they different?
3. Why are there different densities for different wood blocks?
4. What variables make the densities different?
5. How did those differences affect the data?
6. If you haven't already drawn a picture to show how, positioned in water, each fllated, do so.
7. Show the water level on each different block and describe how it relates to their densities.

Formative

1. Densities of different materials can be found in engineering and machinists manuals. After students calculate their densities find a reference book and let students compare their calculations.
2. How are different densities of wood used in different kinds of construction?
Work sheet:

Name _______________
Lab notes - Density of Different Kinds of Wood

What observable measurements can be collected and used to support the idea that different kinds of wood have different densities?

Procedure

Find the volume of each block (l * w * h) in cm or displacement in ml.

Find the mass of each in g.

Calculate the densities.

Prediction: (list the different types in order of their densities)

Data:

Wood Length Width Height Volume Mass Group Density Class average

Kind of wood Mass Volume
Length*Width*Height in cc
or displacement in ml
Density = mass / vol. Class Average

Analysis:

What density did the class get for each wood?

Averages of the class's results:

List the wood in order by their densities.

Can two pieces of wood of different sizes have the same density?

If two objects have the same density are they the same thing?
Why?

If two woods have the same density are they the same kind of wood?
Why?

The density of water is 1 g/cc. Why does wood float on water?

Predict what they would look like when put in water. Draw it.

Try it. what data was observed?

Conclusion: write at least 2 things you learned.

### Activity 10 - Challenges: Finding Density of Different Spheres

Materials:

5-7 spheres. (metal, ping pong, super ball, wood, Styrofoam, marble, plastic), calculators, overflow containers and graduated cylinder to measure water volume, container of water, metric rulers and string if you want to use the diameter for the volume formula, balance beam, container to test the balls, lab sheets

Concepts:

Focus questions:

1. How can you find the density of spheres?
2. How can you use density to predict how spheres will float?

Learning outcomes:

1. Use ideas related to density to solve problems.
2. Measure mass and volume and use it to calculate the density of spheres of different materials.
3. Measure the characteristics of matter in different states.
4. Determine mass and volume of solids and liquids.
5. Calculate the density of various solids and liquids.
6. Record data
7. Predict the relative density of various solids and liquids (using observations).
8. Describe the relationship between mass and volume to density.

Scoring guide

Top level

• Student data for mass, volume, and density should be in the ball park with appropriate unit labels.
• Understand density as related to mass and volume, but not necessarily as a proportion or ratio between them.

Lower level

Suggested procedures overview:

Prior knowledge

Concepts:

• Mass, volume, density, formula for a sphere volume, density of water
• Volume can be measured by submerging each sphere in a container of water and measuring the water displaced by collecting it or marking a starting point and ending point, and finding the difference.
Diameter can be measure and used to calculate the radius (½ diameter)
Calculate the volume of a sphere (Volume = 4/3 pi * radius cubed).

Procedure

Exploration

1. How can you find the density of spheres?
2. How can you use density to predict how spheres will float?
3. Arrange the ball in order according to how well you would predict their ability to float or sink.
4. How can you measure the mass of the spheres?
5. How can you calculate the volume of the spheres?
6. How can you calculate the density of the spheres?
7. What order of densities would you predict?

Invention

1. Float them and observe.
2. Calculate the mass and volume of the sphere.
3. Densities of different materials can be found in engineering and machinists manuals. After students calculate their densities find a reference book and let students compare their calculations.

Formative

Work sheet:

Name _______________

Lab notes -Finding Density of Different Spheres

Which Spheres will float or sink?

Data:

Measure Mass in g Volume in ml or cc

Calculate density g/ml

Label each as a Floater, Sinker or Flinker

Kind of sphere Mass

Volume
Displacement in ml

or V = 4/3 pi * r3

Density = mass / vol. Floater, Sinker or Flinker

Analysis:

Predict the order of densities and draw how you think they will float.

Did any of the balls surprise you?

Which one and why did you think it would not do that?

Conclusion

What other kind of ball would you like to test?

Why?

What do you think would happen to a whiffle ball?

Why?

### Activity 11 - Do Different Liquids Have Different Densities?

Materials:

• Four or five different liquids with different densities that are different colors (alcohol, water, sugar water, salt water, corn syrup, or oil ) If you use alcohol, provide goggles,
• Balance beams, graduated cylinders, droppers or micro pipettes, mL graduated cylinder, calculators, medicine cups or test tubes and rack, Lab notes, small potato chunks - optional

Concepts:

Focus questions:

1. Do liquids have different densities?
2. How can the density of liquids be determined?
3. Can liquids have densities greater and less than one?

Learning outcomes:

1. Identify properties of matter and how to measure - mass & volume.
2. Measure mass and volume of liquids and use it to determine their densities.
3. Use ideas related to density to solve problems.

Scoring guide

Top level

• Student data for mass, volume, and density should be in the ball park with appropriate unit labels.
• Understand density as related to mass and volume, but not necessarily as a proportion or ratio between them.

Lower level

Suggested procedures overview:

Prior knowledge

Concepts:

Procedure

Exploration

1. Show two solids, that they have already measured.
2. Ask. How do the densities compare? One more ...
3. How can we demonstrate this? see if float different, measure calculate, if same vol, measure mass, ...
4. Do liquids have different densities?
5. Ask. How can densities of liquids be compaired?
• Put objects (potato pieces) into liquids and observe how they float.
• Densities of liquids can be compaired by how they layer in a container
• Can compare their mathematical values calculatedby measuring the liquids mass and volume and divide m/v.
• Put the same volume in beakers and measure only the mass.
6. How can the density of liquids be determined?
7. Show four different liquids.
8. Ask. What equipment is needed to find the densities?
9. Ask. What is an procedure (operational definition) to determine density of liquids?
Accept all plans if you can see it heading in a good direction.
Possible operational definition:
1. Measure the mass an empty graduate cylinder.
2. Add the liquid (25 ml).
3. Measure the mass again.
4. Subtract. (mass of liquid & container) - mass of container = mass of liquid.
5. Divide. mass / volume = density
6. Clean out the graduated cylinders between each liquid.
7. Repeat for all liquids.
10. Students collect data and record the results.

Invention

1. Share data and discuss as a class how they collected data and how they used the data to conclude if densities of liquids vary.
2. Compare densities of the liquids and draw explanation pictures.

Formative

1. Can liquids have densities greater and less than one?
2. Densities of different materials can be found in engineering and machinists manuals. After students calculate their densities find a reference book and let students compare their calculations.
Work sheet:

Name _______________

Lab notes - Do Different Liquids Have Different Densities?

Solids have different densities. Do liquids?

What evidence do you have of this?

How does this evidence either convince you or not?

Write a procedure how you might determine density of a liquid.

Procedure:

Carry out the procedure and continue.

Data

If you are satisfied with the results repeat the process for three more liquids and record the information in the table.

Kind of liquid Volume Mass
(m of liquid & container) - m of container = m of liquid
Density = mass / vol. Class average or density Label density from most to least dense.

Analysis

Did the liquids have different densities?

Why do you believe this is so?

Did every group calculate the same density for any liquid?

Why did everyone not get the same densities for the liquids?

Conclusion:

Write and draw pictures to illustrate different densities.

If you poured them together in a tube, what order would you predict?
(sketch and label)

### Activity 12 - Challenges: Relative Density of Plastics

Materials:

4 plastic medicine cups, marker, alcohol, water, salt, three or four different kinds of plastic pieces, tweezers, graduated cylinder, goggles

Concepts:

Focus questions:

1. Do plastics have the same densities?

Learning outcomes:

1. Use ideas related to density to solve problems.
2. Students in small groups will determine the relative density of different plastics using inference.

Scoring guide

Top level

• Arrange the four or five plastic objects by their relative densities.
• Randomly arrange plastic objects.

Lower level

Suggested procedures overview:

Prior knowledge

Measurement concepts include

Procedure

Exploration

1. Show student the materials and challenge them to arrange the plastic objects according to their relative densities.

Invention

1. Share results and discuss the procedures used to determine the relative densities.

Formative

1. What are advantages for different plastics having different densities?
Work sheet:

Name _______________

Lab notes - How is the Density of Plastics Determined?

Purpose: Find density of some plastic pieces through inference.

Materials: 4 plastic medicine cups, marker, alcohol, water, salt, plastic pieces, tweezers, graduated cylinder, goggles

Prediction: order plastic pieces by density?

Procedure:

1. Label the medicine cups 1,2,3 and 4.
2. Put 10 ml denatured alcohol into cup 1
3. Put with 5 ml of water and 5 ml of alcohol into cup 2. Stir.
4. Put 10 ml water to cup 3.
5. Add package of salt to cup 4 and 10 ml water. Stir.
6. Use tweezers to add each piece of plastic to each container.
7. Submerge it and let it go between the bottom and the top of the liquid.
8. Record whether it sinks or floats. Dry the plastic on a paper towel in between trials.

Data:

Plastic object Observation in ______ Observation in ______ Observation in ______ Observation in ______ Label density from most to least dense.

Did all the pieces of plastic have the same volume?

Did they all have the same mass?

Which is the most dense?

How do you know?

Which liquid was most dense?

How do you know?

Conclusion: (two things you learned)

### Activity 13 - Density In School Field Trip

Materials:

• Student worksheet after you get back.

Concepts:

Focus questions:

1. How can density be used to describe human populations?

Learning outcomes:

1. Use ideas related to density to solve problems.
2. Create classroom densities for several classrooms.
3. Standard units are necessary for comparison and better communication.

Scoring guide

Top level

• Related mass to number of students and volume to classroom standard to compute a student density, cooperated and answered questions.
• Started lab, did not complete.
• Equated number of students as density. Not as a relationship of two variables population to a standard area.

Lower level

Suggested procedures overview:

Prior knowledge

Concepts:

Procedure

Exploration

1. Ask. What is the density of elephants in this room?
2. Ask. How can density be used to describe human populations?
3. What would be used for particles of matter (mass)?
4. What would be used for volume?
5. How do we determine the population density of different places in our school?
6. Decide what places to count.
7. Decide how to collect the student population in each of the selected places.
8. Decide what time to collect the data.
9. Safety issues or specialized background knowledge: Notify the administration and others in areas to be counted. What you and your class are doing and get permission to be wandering around the building at certain times.
10. Collect data.

Invention

1. How can the data be standardized?
2. Example: A person can be a unit for mass.
3. A certain sized classroom can be a unit for volume or area.
4. How to equate other school places to the standard unit for area. Example how many classroom units would the gym, auditorium, lunch room, offices, football stadium, equal.
5. Organize data according to standard unit decisions.
6. Share data.
7. Discuss.

Formative

1. Find some population density maps and explain how different regions vary and what that means for population differences.
Work sheet:

Name _______________

Lab notes - Density In School Field Trip

Data

Place & time Population Space Density Label density
from most to least dense

Analysis

Where on the field trip was the density the highest?

Why?

Where on our field trip was the density the lowest?

Why

What does volume have to do with density?

What does mass have to do with density?

As mass (the class) left a smaller room, what happened to the density?

Explain

Conclusion: Describe two things you learned.

### Activity 14 - Challenges: Density of a Gas

Materials:

• plastic bags, plastic tubing, goggles, Alka Seltzer or generic (much cheaper) stomach aid tablets, worksheet, apparatus pictured below

Concepts:

Focus questions:

1. Do gases have density?
2. How do you determine the density of a gas?

Learning outcomes:

1. Collect the gas released from a seltzer tablet, measure its volume, mass, and calculate its density.

Scoring guide

Top level

• Student data for mass, volume, and density should be in the ball park with appropriate unit labels.
• Understand density as related to mass and volume, but not necessarily as a proportion or ratio between them.

Lower level

Suggested procedures overview:

Prior knowledge

Concepts:

Procedure

Exploration

1. Ask. Do gases have density?
2. How do you determine the density of a gas? (Find volume and mass.)
3. Ask how that might be done. Possible answer - fill a bag with a gas (blowing into it) find its mass and volume and calculate the density.
4. Mention. Large trash bags are sold by their volume. Therefore, we might be able to take one, mass it, fill it with air, mass it again, and calculate density.
5. You may discover the mass is no different if the bag has air or not as most middle school balances cannot easily detect the difference between small masses.
6. The volume of smaller bags can be measured by placing it in a large beaker or 2 liter plastic bottle with the top removed and setting something on top of it to hold it down so as to level the top so the volume can be read or mark the plastic bottle and determine the volume to that point.
7. Mention another way to measure density of a gas is to measure the mass of a material that will produce the gas before and after.
8. Describe a procedure to generate a gas and collect it. Diagram in lab notes.
1. Fill a test tube about ⅓ full with water.
2. Find the mass of the test tube, water, and ½ seltzer tablet.
3. Set up the equipment as pictured. The graduated cylinder needs to be full of water and upside down. First fill it, then hold your hand over the top and put it in the bucket.
4. Drop the alka seltzer in the test tube and put on stopper. Wait for bubbles to stop.
5. Write down where the water level is in the graduated cylinder and turn right side up.
6. Mass the test tube water and seltzer mixture.
9. Ask students conduct the experiment as a class deomonstration or in student groups.
10. Post results on the board or an overhead

Invention

1. Discuss the data, calculate the density, and discuss.
2. Why did you mass the materials before and after the gas escaped?
3. Why was there less mass after the experiment was over?
4. If multiple groups generated data, calculate a class average for the seltzer gas.

5. Ask. What kind of gas was generated? carbon diooxide.
6. Mention. The density of carbon dioxide is about .002 (If you can get within a decimal place you have done well).
7. Discuss sources of error. Rounding, scale, human, ...
8. Conclude. All measurement has errors.
9. The density of this gas is .002 as determined in a better equipped lab. The density of air is about .0013. If we let this gas out, would it rise or sink?
10. Describe all the characteristics of this gas that you know (color, smell, density) and how is it different from air? Most important it will sink to the bottom of containers, rooms, and take the place of oxygen making it deadly for animals including humans.

Formative

1. What would you predict to be the range of densities for worldy gases?
2. Would you conclude all gases are less dense than one (water).
Work sheet:

Name _______________

Lab notes -Measuring the Density of a Gas

How is the density of a gas measured?

How does it compare to density of solids and liquids? Procedure:

1. Fill a test tube about ⅓ full with water.
2. Find the mass of the test tube, water, and ½ seltzer tablet.
3. Set up the equipment as pictured. The graduated cylinder needs to be full of water and upside down. First fill it, then hold your hand over the top and put it in the bucket.
4. Drop the alka seltzer in the test tube and put on stopper. Wait for bubbles to stop.
5. Write down where the water level is in the graduated cylinder and turn right side up.
6. Mass the test tube water and seltzer mixture.

Prediction: (what do you think the density of this gas will be?)

Data:

1. mass of test tube, water, and ½ seltzer tablet before ______g
2. mass of test tube, water, and ½ seltzer tablet after ______g
3. change in mass ______g
4. volume of gas ______ml
5. density ______g/ml

Analysis:

What is the class average for the alka seltzer gas?

Why did you have to mass the materials before and after the gas escaped?

Why was there less mass after the experiment was over?

The density of this gas is .002 as determined in a better equipped lab. The density of air is about .0013. If we let this gas out, would it rise or sink?

Describe all the characteristics of this gas that you know (color, smell, density) and how is it different from air?

Conclusion:

### Activity 15 - Challenges: Comparing Density of Liquids May use as a performance assessment

Materials:

• 25 mL graduated cylinders, balance, test tube and rack, 4 liquids (water, salt water, alcohol, vegetable oil, corn syrup, glycerin, liquid dishwashing soap etc) food coloring should be used to differentiate the clear liquids into recognizable colors, student lab sheet

Concepts:

Focus questions:

1. How can different densities of liquids be used?

Learning outcomes:

1. Use ideas related to density to solve problems.
2. Students find the volume and mass of liquids and determine density as a relationship between the two liquids for four liquids.

Scoring guide

Top level

• Describes density as a proportional relationship of mass and volume.
• Described density as a relationship of mass and volume (not proportional).
• Completed lab sheet. Says mass and volume relates to density, (not how relates).
• Parts of the worksheet are not complete. Mentions mass, volume, and density (no mention of them being related).

Lower level

Suggested procedures overview:

Prior knowledge

mass, volume, density, how to use a graduated cylinder to measure volume and a balance to measure mass.

Concepts:

Procedure

Teacher notes:

Better accuracy can be gained by using more liquid, but increased liquid increases the cost. May want to use different volumes for different substances (10 ml glycerin - 100 ml water or may want to return substances to original containers - not good lab technique, but sometimes necessary when supplies are limited). When students work in groups they can check each others work. Plan ahead for clean-up. May or may not want to provide students with density formula or let them suggest ways to compare the mass and volume of liquids.

Exploration

1. How did we compare the density of solids? (By floating them in liquids such as water.)
2. What about the density of liquids?
3. How can they be compared?
4. How can different densities of liquids be used?
5. In this activity you will learn about density of liquids.
6. Ask. How does volume and mass describe the matter (stuff) in the liquids. Volume is space it takes up. Mass is the amount of matter in it.
7. Ask. What differences they would expect between the different liquids. Different densities.
8. Ask. How they could collect data to substantiate their claims. Measure the mass and volume and use them to calculate densities.
9. Allow students to work and record their results.
10. Display a class averages for each liquid.

Invention

1. Display results for everyone to view.
2. Allow students to work on analysis questions.
3. Review their answers and discuss them.
4. Ask. Why it makes more sense to density sometimes rather than mass or volume? It is a relationship between mass and volume or how much mass (matter) per volume (space).
5. Discuss results with students, then ask. How can different densities of liquids be used?
6. One example is to layer them as a parfait.
7. Challenge students to create a parfait.

Formative

Complete the States of Matter - Summary Chart

States of Matter - Summary Chart

4 States of Matter Solid Liquid Gas Plasma
Volume/ Mass/ Density Definite Volume
Definite Mass
Definite Density
Definite Volume
Definite Mass
Definite Density
No definite volume
Definite mass
No definite density
No definite volume
Definite mass
No definite density
Shape Definite shape
0000000000
0000000000
0000000000
No definite shape
000000000
0000000000000
00000000000000
00000000 0 0 0

o
No definite shape 0
0         0     0      0
0       0           0     0
0          0                0
o
No definite shape 0
0                     0
0                 0
0                      0
Proximity to other atoms (packed?) Fixed position
Locked into place
Tightly packed
Not fixed, n
Not locked
Loosely packed
No proximity to other atoms No proximity to other atoms
Action
(Type of movement/collisions)
Vibrate in place Roll or slide over each other.
A few collisions
Bounce and collide Fast movement
Electrons stripped off
Energy Level Low Medium High Extremely high
Examples Rock
Paper
Scissors
Water
Juice
Tea
Molecular Oxygen
Molecular hydrogen
Water vapor
Star
Lightening
Incandescent bulb
Compressibility Most very little Most very little Best very able Can with extreme pressure - stars - gravity, magnetic
Measured with Cubic cm or meters Liter, ml, qt. Gal. Cubic

Work sheet:

Name _______________

Lab notes -Measuring Metal Cubes: mass, volume, & density

Introduction: The density of solids can be compared by floating them in liquids such as water. But what about the density of liquids? How can they be calculated and compared? In this activity you will learn about density of liquids.

Materials: graduated cylinder, balance, 4 liquids (vegetable oil, alcohol, water, glycerin…).

Prediction: Which liquid do you think will be most dense?

Least?

Procedure:

2. Pour one liquid into it. Find the mass now and record it.
3. Fill in the volume and mass measurements in the data table and calculate the density of the liquid by dividing mass by volume.
4. Carefully clean out your graduated cylinder and repeat for each liquid.

Data:

Liquid Mass of graduate cylinder Mass of graduated cylinder & liquid Mass of liquid Volume of liquid Density of liquid

Analysis:

Which liquid is most dense?

What are two ways you know this?

A milliliter and a cubic centimeter are the same size. Why use milliliters to measure liquids?

When would cubic centimeters be more useful?

Does the “thickness” or stickiness of liquid predict its’ density?

How?

Conclusion:

1. Use your data to decide what order to pour a small amount of each liquid into the test tube to make a parfait (a four layered liquid).
2. Draw and label the results.

States of Matter - Summary Chart

4 States of Matter Solid Liquid Gas Plasma
Volume/ Mass/ Density

Shape

Proximity to other atoms (packed?)

Action
(Type of movement / collisions)

Energy Level

Examples

Compressibility

Measured with

### Activity - Practice Measuring Liquid Volume with a Graduated Cylinder

Materials:

• 3 large containers of red, yellow, and blue water - distilled water colored with food coloring
• 3 small containers or cups per student group
• 6 test tubes or small medicine containers and 1 test tube rack (if use test tubes) per student group
• 1 - 10 ml or 25 ml graduated cylinder per student group

Concepts:

Focus questions:

1. How do you calculate density of liquids?

Learning outcomes:

1. Measure mass and volume and calculate density.
2. Use ideas related to density to solve problems.

Scoring guide

Top level

• Student data for mass, volume, and density should be in the ball park with appropriate unit labels.
• Understand density as related to mass and volume, but not necessarily as a proportion or ratio between them.

Lower level

Suggested procedures overview:

Prior knowledge

• Primary pigment colors are: red, blue, & yellow. Mixing them creates secondary colors: green, purple, orange.
• Measuring liquid volume in milliliters with a graduated cylinder.
• Hypothesis can be created by describing a relationship between variables. Multiple variables can be used to describe a relationship.

Procedure

Exploration

1. Students follow a written procedure to create six colors of the rainbow from three primary colors.
2. Put students into groups and give each group three small containers or cups, a graduated cylinder, and six medicine containers or a test tube rack with six test tubes.
3. Tell. Follow the procedure on the Lab Notes page and make six colored liquids.
4. When the students have the six colored liquids, then ask them to conduct an inquiry activity to create and write their own "recipes" for making cool colors in the medicine cups or test tubes.
5. Allow the students to explore with their colors and see what they create.
6. Emphasize that all color combinations or recipes must be carefully measured and recorded in their Lab notes so they can explain to the other groups how they might create those colors or how they can keep the company secret recipe to make more.

Invention

1. Results after mixing the colored liquids:
2. Test Tube Color Action Total Volume of Water (mL) and Color
Test Tube Color Action Total Vol. (ml) Color
A 9.5 ml Red - 4.0 ml to B 5.5 ml red
B + 4.0 ml from A + 1.5 ml from C 5.5 ml orange
C 9.0 ml yellow - 2.0 ml to D - 1.5 ml to B 5.5 ml yellow
D 2.0 ml from C + 3.5 ml from D 5.5 ml green
E 9.0 ml blue - 3.5 ml to D 5.5 ml blue
F 2.0 ml Blue + 3.5 ml Red 5.5 ml

purple

Operational definition:

Increase color _________ with _________ makes it ______________.

Increase color ____________ and color __________ makes it _____ ________.

Notice how two variables combine to affect a third variable. (formal operational characteristic)

Formative

1. When students have the six colored liquids, ask them to conduct an inquiry activity to create and write their own recipes for making cool colors in the medicine cups or test tubes.
2. Allow the students to explore with their colors and see what they create.
3. Remind students all color combinations or recipes must be carefully measured and recorded in their Lab notes so they can explain to the other groups how they might create those colors or how they can keep the company secret recipe to make more.
Lab sheets:

Name _______________

Lab notes - Making a Rainbow
Measuring Liquid Volume with a Graduated Cylinder

Purpose: In this activity you will use a graduated cylinder to measure volume in the metric system.

Materials:
Red, blue, and yellow water, created with red, blue, and yellow food coloring, 3 cups, 6 small containers or test tubes with test tube holder, small graduated cylinder, eye dropper

Procedure:

1. Label each small container A, B, C, D, E, or F
2. Pour about 25 mL of each or the three colors (blue, yellow, and red) of water into three cups to use to make a rainbow of colors in the containers A - F.
3. Measure 9.5 ml of red water into container A
4. Measure 9 ml of yellow water into container C
5. Measure 9 ml of blue water into container E
6. Measure 2 ml from container C and pour pour it into container D
7. Measure 3.5 ml from container E, pour it to test tube D,
8. Measure 2 ml of blue water into container F,
9. Measure 3.5 ml of red water into container F,
10. Measure 4 ml of water from container A and pour it into container B
11. Measure 1.5 mL of water from container C and pour it into container B

Observations and Data:

Measure the total amount of water in each medicine container or test tube. Record it and the final color in the chart below.

Test Tube Color of Water Total Vol. (ml)
A
B
C
D
E
F

Conclusion: Write two things you learned from this lab.

Lab notes - Creating More Colors

Purpose:

Materials:

Red, blue, and yellow water, medicine cups or test tube stand and 6 test tubes, 3 small containers or cups, small graduated cylinder

Procedure:

1. Continue your investigation and create a color pallet of six colors with combinations of the primary colors.
2. It is your choice to select at four of your six colors.
3. Record the recipe for each color you select as part of your pallet to share with the class.

Recipes for four colored liquids.

Conclusions — How could you use or extend what you found?