TEKS Review
3.5C
Name ______________________________________ Date _________
TEKS 3.5C predict, observe, and record changes in the state of matter caused by heating or cooling
Changes in States of Matter
What Is Matter?
Anything that has mass and takes up space
is matter. All physical objects are made of
matter. If you could view an object through the
most powerful microscope, you would see that
matter is made of tiny particles called atoms.
Different types of matter are made of different
arrangements of atoms. Each type of matter has
physical properties that you can see, smell,
touch, taste, measure, and study.
States of Matter
You know that different kinds of matter
have different properties. Helium, water, and
aluminum, for example, are very easy to tell
apart. At room temperature, each of these kinds
of matter exists in a different state. One is a
solid, one is a liquid, and one is a gas. Do you
know which is which?
At room temperature, helium
is a gas. A gas is the state of matter
that expands to fill its container.
A gas does not have a definite shape
or volume. Helium gas is used to
fill balloons.
Water is a liquid at room temperature. A
liquid is the state of matter that has a fixed
volume but not a definite shape.
A liquid takes the shape
of its container. You
can pour liquid water
from a pitcher
to a glass.
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Aluminum is a solid at room
temperature. A solid is the state of
matter that holds its own shape and
has a fixed volume. You can bend
and tear a sheet of aluminum foil,
but the total volume of aluminum does
not change.
Solids keep their shapes. Liquids flow.
Gases fill their containers. Why? You can
answer this question by thinking of matter as
being made of tiny particles that are in motion.
The state of matter is dependent upon the
amount of energy the matter contains.
The particles in a solid are packed very
close together. They vibrate in place, but they
can’t slide past one another. This gives a solid
its definite volume and shape.
The particles in a liquid are not as close
together. They have more energy and can move
past one another. This enables a liquid to flow.
The particles in a gas have a lot of energy.
They are not very close together and move the
fastest. They spread out to fill their container.
The particles are so far apart that they can be
squeezed together. That’s what you do when
you pump up a ball or a tire. You squeeze more
gas into the ball or tire, which gives it pressure.
TEKS 3.5C
solid
liquid
gas
Page 1 of 6
Name ______________________________________ Date _________
Changes in Matter
Matter can go through physical and
chemical changes. A physical change does not
change what a substance is. When paper is cut,
shredded, or torn, it is still paper. This is a
physical change. A chemical change results in a
new substance being formed, and energy is
either given off or absorbed. When paper is
burned, it turns new forms of matter—hot gases
and ash.
Changes in State
You learned that some kinds of matter are
solid at room temperature. Other kinds of matter
are liquid or gas at room temperature. Did you
know that each kind of matter can exist as a
solid, a liquid, or a gas?
The temperature of matter determines its
state. As heat is added, the particles of matter
begin to move faster. As heat is taken away, the
particles move slower. When enough heat is
added or taken away, matter can change state.
For example, aluminum foil will turn into a
liquid if its temperature reaches 660°C
(1,220°F). It is still aluminum, but it is no
longer a solid. This is a change in state. Changes
in state are physical changes.
Let’s take a closer look at water. Water is a
liquid at room temperature. If you put it in a
freezer, its temperature
decreases. The particles of
water begin to slow down.
At temperatures below
0°C (32°F), water freezes.
Freezing is the change from
a liquid to a solid. Solid water
is called ice.
If you remove an ice cube from the freezer,
it slowly warms. The particles of water begin to
move faster and slide past one another. At
temperatures above 0°C, ice melts. Melting is
the change from a solid to a liquid.
Ice is solid
water. It melts
and becomes
liquid water.
Place a pot of liquid water on a hot stove,
and the water gets warmer. When it reaches
100°C (212°F), it boils. Boiling is the rapid
change from a liquid to a gas. Sometimes,
particles near the surface of a liquid move fast
enough to become a gas, even if the temperature
is not at the boiling point. This is called
evaporation, which occurs slowly and only at
the surface of a liquid.
To form a seal between two metal pipes,
a welder heats metal so it turns into a
liquid that can be formed into a certain
shape.
TEKS Review and Assessment
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TEKS Review
3.5C
The boiling
point of water
is 100°C.
TEKS 3.5C
Page 2 of 6
TEKS Review
3.5C
Name ______________________________________ Date _________
When a gas turns to a liquid, the process is
called condensation. You have seen this
process occur when water drops form on the
outside of a cold glass. It might look like the
glass is leaking, but that’s not the case. Water in
the form of a gas is called water vapor. It’s in
the air all around you, but you can’t see it. The
water vapor’s temperature is cooled by the cold
glass. The decrease in temperature causes the
water vapor to condense and form droplets of
liquid water.
Condensation is
the process of
turning a gas into a
liquid. We also call
the physical drops
of liquid that form
condensation.
Hands-On Activity
Observing States of Matter
Materials
The state of matter can change based on the amount of energy in
the substance. Matter can exist as a solid, a liquid, or a gas. In this
activity, you will examine water in each of these states.
Procedure:
•
•
•
•
ice cubes
water
hot plate
freezer-strength
zip-top bags
1. Place a few ice cubes in a zip-top bag. Pass the bag around. Squeeze and press the bag.
What happens? In a small group, discuss the properties of the ice. Include temperature,
texture, shape, and color in your discussion.
2. Pour some water into a zip-top bag, and seal it. Pass the bag around. Gently squeeze and
press the bag. What happens? Discuss the properties of the water. Include temperature,
texture, shape, and color in your discussion.
3. Watch as your teacher holds a zip-top bag over boiling water to capture some water vapor.
The water vapor is mixing with the air around you. Pass the sealed bag around the
classroom. Gently squeeze and press the bag. What happens? Discuss the properties of the
water vapor and other gases in the bag. Include temperature, shape, and color in your
discussion.
Discussion Questions:
1. What differences did you notice in the different states of water?
2. What are other examples of solids, liquids, and gases?
TEKS Review and Assessment
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TEKS 3.5C
Page 3 of 6
Name ______________________________________ Date _________
TEKS Review
3.5C
Changes in States of Matter
Write a definition for each term below.
freeze
___________________________________________________________________
boil
___________________________________________________________________
condense
___________________________________________________________________
Suppose an ice cube is taken out of the freezer. Predict how it will change over several hours.
___________________________________________________________________
___________________________________________________________________
___________________________________________________________________
Complete the cause-and-effect graphic organizer below.
Cause
Effect
The liquid evaporates.
Complete the Venn diagram below to compare and contrast melting and boiling.
Melting
Both
TEKS Review and Assessment
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TEKS 3.5C
Boiling
Page 4 of 6
Name ______________________________________ Date _________
TEKS Review
3.5C
TEKS Assessment 3.5C
Fill in the letter of the best choice.
Which is the process by which a gas
becomes a liquid?
Which of the following is correct?
evaporation
condensation
melting
boiling
What happens to the particles of matter
when a liquid changes to a gas?
They stop moving.
They vibrate in place.
They move faster and spread out.
Only water can exist as a solid, a
liquid, and a gas.
The solid form of water is called
water vapor.
A change of state is a chemical
change because a new kind of
matter is formed.
At the right temperature, any kind
of matter can exist as a solid, a
liquid, or a gas.
Look at the thermometer below.
They slow down and begin
bumping into one another.
Look at the drawing below.
Which prediction is correct?
The ice will melt, and condensation
will form on outside of the glass.
The ice will evaporate before it
finishes melting.
The ice will boil, and water will
spill on the outside of the glass.
The ice will condense and stick to
the outside of the glass.
TEKS Review and Assessment
© Houghton Mifflin Harcourt Publishing Company
TEKS 3.5C
What properties does water have at this
temperature?
It would fill its container.
It would hold its own shape.
It would not have a shape.
It would take the shape of its
container.
Page 5 of 6
Name ______________________________________ Date _________
TEKS Review
3.5C
Answer Key
Hands-On Activity (p. 3)
1. Students should note that the ice (solid water) had a definite shape, was hard, and was cold.
The liquid water was not cold, changed shape when the shape of the bag was changed, and
did not fill the bag completely. The water vapor filled the entire space inside the bag. It
was not possible to see the water vapor.
2. Answers will vary. Sample answers: Helium in a balloon, the air we breathe, propane in a
stove, and natural gas that heats a home are examples of gases. Examples of liquids
include honey, vinegar, soda, juice, and gasoline. Most of the objects used in the
classroom are solids, including desks, books, pencils, paper, and backpacks.
Student Response Activity (p. 4)
1. To freeze is to change from a liquid to a solid. To boil is to turn rapidly from a liquid to a
gas. To condense is to change from a gas to a liquid.
2. When an ice cube is taken out of the freezer, heat energy will move into the ice cube and
the ice cube will begin to get warmer. As the temperature gets above 0°C (32°F), the ice
will melt. Liquid water on the surface may evaporate, or turn in to a gas. The puddle of
water formed will eventually dry up if given enough time to evaporate completely.
3. The particles on the surface of a liquid get enough energy and move fast enough to escape
from the other liquid particles.
4. Melting—changing from a solid to a liquid; Boiling—changing from a liquid to a gas;
Both—changes in state, require addition of energy
TEKS Assessment (p. 5)
1. B
2. C
3. A
4. D
5. D
TEKS Review and Assessment
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TEKS 3.5C
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