2 What Makes Up Matter?
LESSON GOALS
You will learn
• what makes up matter.
• how particles of matter
move.
SCIENCE IN YOUR LIFE
Some matter has only
one kind of atom. You
breathe oxygen from the
air. All the atoms of
oxygen are the same.
Other matter has more
than one kind of atom.
Two different kinds of
atoms join together to
make water.
atom (at/om), a small
particle that makes up
matter.
Small particles make up
matter.
100
Imagine looking at a pin like the one in the
first picture. The tiny pin can be hard to see.
Now imagine adding more pins like those in
the second picture . You can see the group of
pins more easily than one pin. Each pin is like
a small particle of matter. The group of pins is
like matter you can see.
Particles in Matter
The particles that make up matter are called
atoms. You cannot see atoms because they are
so small. Two or more atoms can join together
to form larger particles of matter. Then many
of these larger particles can join together to
form the matter you see.
Scientists know about many kinds of atoms.
These atoms can join together in different
ways to make different kinds of matter.
How Particles of Matter Move
Particles in matter are different in different
states of matter. The pictures show how the
particles in a solid look different from those in
a liquid. Which state of matter has particles
that are closer together?
The particles in solids pull toward each
other. A solid keeps a certain shape because its
particles stay close together. The particles in
matter are always moving. Particles in solids
move back and forth, but they do not exchange
places.
Notice how the particles in liquids are
farther apart than those in solids. The pull
between particles is weaker in liquids than in
solids. Liquids change shape because the
particles can move around each other.
a
o
Particles in a liquid
Particles in a solid
\)0
00
00
° °0
°0°0
0°0
°
0°
0°0
°oOcOoO'~-
GoOn
000
o~o
o
)0
°Vo
OOo~-----0
00
~o
a
a
101
-0 0
Particles in a gas
o
0
o
o
0
o 0
0
0
00 0 0 0
o 0
0
o 0 0
o 0 0
0
o
o
0
0 0
~'" 0
o
0
0
0
o
o o
0
o
0
The particles in gases do not pull together
strongly. Notice how much space separates the
gas particles in this drawing. Gas particles
move around more than particles in liquids and
solids. A gas can spread out to fill any space
because its particles move around freely.
Lesson Review
1. What makes up matter?
2. How do particles move in solids, liquids,
and gases?
3. Challenge! Can a container of gas be only
partly full? Explain your answer.
Study on your own, pages 324-325.
FIND OUT
ON YOUR OWN
102
Draw a picture of a glass of water. Now
imagine adding several drops of grape juice
to the water. Color the picture to show
how the liquid would look. Write a few
sentences explaining what would cause the
color to change.
·LESSON 2
pages
100-102
1. Two or more $1. join to form larger particles of
matter.
2. A solid has particles that are ::rt; than the
particles in liquids.
3. How do liquids change their shape?
4. In which of the states of matter do the particles
have the weakest pull?
5. A @f can spread to fill any space.