TEACHER RESOURCES
G2 – Changes in Matter
TEKS 2.5 Matter and energy. The student knows that matter has physical properties
and those properties determine how it is described, classified, changed, and used.
The student is expected to:
(B) compare changes in materials caused by heating and cooling.
(C) demonstrate that things can be done to materials to change their physical properties
such as cutting, folding, sanding, and melting.
Background Knowledge
Students should be able to name some physical properties such as, liquid, solid, and
temperature (hot or cold). They should be able to describe the change in materials due to
heating and cooling. They should also be able to explain that things can change shape,
size, texture, but they are still the same material.
All physical materials have properties such as size, shape, temperature, and mass,
flexibility— solid and liquid.
When physical properties of materials are changed, this does not mean it is a different
material. Water is still water whether it is a solid (ice) or a liquid. A piece of paper can be
folded, torn, or cut. The physical properties change (shape, mass, size) but it is still paper.
A piece of wood can be rubbed with sandpaper, and the texture will become smooth.
Students should recognize and describe these changes in physical properties. In the case of
water, as well as other substances, if you remove heat (put in the freezer) it becomes a
solid. If you add heat (take it out of the freezer), the solid becomes a liquid. This is true of
many other common liquids. Some materials are solid at room temperature, and become
liquid when heated, such as chocolate, candle wax, and butter.
Essential Questions
How do some materials change when they are heated?
(Some materials melt or change state when heated.)
How do some materials change when they cool?
(Some liquids become solid when cooled.)
What are some physical properties of materials?
(Physical properties include size, shape, color, texture, mass, taste, scent, and
temperature.)
© 2011-2013 Edumatics Corporation
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TEACHER RESOURCES
G2 – Changes in Matter
I’m Melting
Objective:
To describe what happens when ice melts, and to relate the rate at which the ice melts to a
difference in the amount of heat energy present.
Materials:
zip top sandwich bags
ice cubes
plastic beakers
stopwatches
clocks
How to Conduct:
Divide class into groups of three. Hand out two plastic bags with an ice cube in each to
each group. Have students place one bag in the shade and the other in the Sun.
Instruct them to observe the two bags till the ice melts completely. Have the students use
a stopwatch to record the melting time for the bag in the sun and a clock for the bag in the
shade. Have the students use plastic beakers to measure the amount of water in each bag.
Ask the students:
1. What happened to the ice cubes? What caused the change?
2. Which ice cube melted faster? Why do you think it melted faster?
3. What properties of the ice cube changed when it melted?
4. How can you change the liquid water back to an ice cube?
© 2011-2013 Edumatics Corporation
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TEACHER RESOURCES
G2 – Changes in Matter
Heat It Up
Objective:
Students will be able to describe the change in properties of several common items when
they are heated and then cooled.
Materials:
chocolate bar
stick of butter,
candle, lighter,
hot plate or hair dryer
pan
goggles (per student)
Safety: This demonstration requires caution due to the use of heat. Make sure students do
not touch the lighted candle or the hot wax, and use caution when using the hot plate. Ask
students to discuss with their lab partners why it is important to wear goggles when
heating substance. Then have them share with the class.
How to Conduct:
Gather the students around a demonstration table and light a candle. While it is burning,
discuss how the candle had the property of being solid. Compare this to ice that is not
solid at room temperature.
Ask students: “Why is water only a solid when it is cold?” Lead them to infer that a
candle needs more heat than water to be a liquid.
By this time there should be candle wax dripping. Ask the students: “What made the
candle drip wax?” Then, “What happens to the wax when it drops on the table?” “Why
does it become a solid again?” Discuss with students that different materials become
liquid at different temperatures.
Then, show them the chocolate and the butter. Let a few students touch both and describe
some of their physical properties. Lead them to name the properties of a solid (solids have
a fixed shape and takes up the same amount of space no matter where it is placed). Use the
hair dryer or the hot plate and pan to melt each one, and discuss the change from a solid to
a liquid. Ask: “How can we make them solid again?”
Put both items in a refrigerator, and take them out later in the day to observe the results.
© 2011-2013 Edumatics Corporation
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TEACHER RESOURCES
G2 – Changes in Matter
Changes
Objective:
Students will make physical changes to various items and describe the changes in
properties.
Materials:
Construction paper
scissors
new crayons
a double pan balance
How to Conduct:
Put students in three groups. One group will fold their paper into different shapes. The
second group will cut their paper into different shapes and sizes. The third group will
color their paper and cover the paper as much as possible with color. This should be done
in about five minutes.
Gather in large group and discuss the changes each group made to their paper. The
changes for group one should be size and shape. Ask: “How did your paper change? Is it
still paper even though it changed?”
Discuss the changes for group two. They should recognize changes have occurred in size
and shape also. Ask: “How has the mass of the paper changed?” Use an uncut sheet of
construction paper and the cut paper pieces from one group, and a double pan balance to
show that the mass has not changed.
Discuss changes for group three. The property of color has changed for the paper. Also,
get them to observe their crayons. Ask: “What properties of the crayons have changed?”
Get students to describe the change in size and shape. “Where did the crayon wax go?”
Ask students to brainstorm other common items in the classroom, and the changes that can
be done to change their physical properties.
© 2011-2013 Edumatics Corporation
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