Study Guide for “Changes”
Lesson One: “Thinking About How Things Change”
The students studied Change Cards with their group and
discussed how the matter in the pictures may change.
Question: What causes things to change? If you could
be a solid, liquid or gas what would you choose and why?
Important Ideas:
 Matter is all around us.
 You can taste, touch, see, or smell matter.
Matter can change forms.
There are three States of Matter ~ solid, liquid, and gas.
Properties is another word for characteristics. Properties describe what something looks
like, feels like, or smells like, etc.
A solid has a definite size and shape.
Liquid takes up space, can be poured, and takes on the shape of its container.
Gas has no definite shape and takes on the shape of its container.
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Lesson Two: “Freezing and Melting”
 The students discussed the properties of water as a solid and liquid. They investigated ways to
melt an ice cube in a ziploc bag. Then they poured the water in an open Petri dish for the next
lesson.
Question: What causes matter to melt? How are freezing and melting related?
What is the fastest way to melt an ice cube in a ziplock bag?
Important Ideas:
 Freezing changes a liquid to a solid because heat is removed from the
liquid.
 Melting changes a solid to a liquid because heat is added to the solid.
Lesson Three: “Where did the Water Go?”
 The students discussed the properties of water as a gas.
Question: What would happen if the water cycle stopped working? What does evaporation mean?
Why does water evaporate? Where does water go when it evaporates? What happens to a liquid
over time?
Important Ideas:
 Gas is usually invisible. You can feel gas from wind, heat or cold.
 As part of the water cycle, water on earth continually changes from a liquid to a gas and
then back again. The sun warms the water on earth. As the water heats up, some of it
escapes into the air as water vapor ~ gas during evaporation. The water in the air mixes
with dirt and forms clouds ~ condensation. When the water in the clouds become too heavy,
it falls as rain or snow ~ precipitation. The water then ends up back on earth, and the water
cycle begins all over again.
Lesson Four: “Mixing and Separating Solids”
 The students discussed the properties of the solids gravel and salt. Then they mixed them and
later separated them back to their original state.
Question: What would happen if you mixed two solids together? If you make a mixture of two
different solids, can they be separated back to their original states?
Important Ideas:
 A mixture is a blend of two or more substances.
 You can separate mixtures.
Lesson Five: “Mixing Solids and Liquids”
 The students discussed the properties of the solids gravel, tissue, and salt and the properties
of the liquid water. Then they mixed them and discussed the results of each mixture. Then
they poured the salt water into an open Petri dish for the next lesson.
Question: How is mixing two solids together different than mixing a solid and a liquid? If you
make a mixture of a liquid and a solid, can they be separated back into their original states?
Important Ideas:
 The gravel showed little change.
 The tissue broke down into smaller pieces.
 The salt dissolved into the water.
Lesson Six: “Changing Salt Water to Crystals”
 The students observed the properties of the salt after the water evaporated. They discussed
possible reasons why the salt crystals were formed.
Question: When salt water evaporates, why does the salt stay in the petri dish? How is the salt
different? How is the salt the same?
Important Ideas:
 The water and salt mixture changed over time through evaporation. The liquid water
escaped into the air and became a gas. The solid salt crystals were left behind.
Lesson Seven: “Separating Mixtures of Color”
 The students observed the change that occurred when water was added to a water-based
marker’s ink on paper.
Question: How can water change different kinds of matter?
Important Ideas:
 Black ink can be separated into many colors.
 Some colors separate more than others.
Lesson Eight: “ Making Carbon Dioxide”
 The students observed and discussed the change that occurred
when a solid effervescent tablet was put into a cup of liquid
water. The teacher read and explained “Putting the ‘Pop’ in Soda
Pop.”
Question: Why do you think soda pop has bubbles?
Important Ideas:
 Matter can change shape.
 Matter can change states.
 Solids can dissolve in water, but they don’t disappear!
 Carbon Dioxide is a type of gas.
Lesson Nine: “ Bubbles and Fizz”
 The students discussed and recorded the properties of water, baking soda, and vinegar. Then
they made two mixtures ~ 1. water and baking soda and 2. vinegar and baking soda. The
students then compared the differences and discussed the changes that occurred between the
two investigations.
Question: How do you know when a chemical reaction has occurred?
Important Ideas:
 Chemical reactions happen when substances encounter each other and form a brand new
substance.
 A chemical change occurs when baking soda and vinegar are mixed.
 When the gas carbon dioxide is cooled, it changes to a liquid and can be poured.
Lesson Ten: “Gas in a Bag”
 The students observed and discussed that gas takes up space and has volume.
Question: What would happen if you trap a chemical reaction in a bag?
Important Ideas:
 A gas, indicated by bubbles, can be trapped and takes up space.