The Particle Model Of Matter Worksheet Page 2

ADVERTISEMENT

The particles in a solid are held together strongly. The spaces
between the particles are very small.
A
has a fixed shape and a fixed volume because the
solid
particles can move only a little. The particles vibrate back and
forth but remain in their fixed positions.
As a solid is heated, the particles vibrate faster and faster until
they have enough energy to break away from their fixed positions.
When this happens, the particles can move about more freely. The
change from a solid to a liquid is called
melting.
The reverse of melting is called
or solidification. This is
freezing
the change from a liquid to a solid. As a liquid cools, the particles
in the liquid lose energy and move more and more slowly. When
they settle into fixed positions, the liquid has frozen or solidified.
The particles in a liquid are separated by spaces that are large
enough to allow the particles to slide past each other.
A
liquid
takes the shape of its container because the particles
can move around more freely than they can in a solid. They are
held close together, however. Therefore, a liquid has a fixed
volume, like a solid.
When a liquid absorbs heat energy, the particles move about
more and more quickly. Some of the particles gain enough
energy to break free of the other particles. When this happens,
the liquid changes to a gas. The change from a liquid to a gas is
called
evaporation.
The reverse process—the change from a gas to a liquid—is called
condensation.
As a gas cools, the particles in the gas lose energy
and move more and more slowly until the gas condenses to a liquid.
The particles in a gas are separated by much larger spaces than
the particles in a liquid or a solid. Therefore, a gas is mostly
empty space.
A
always fills whatever container it is in. Since the particles
gas
are moving constantly in all directions, they spread throughout
their container, no matter what volume or shape their container is.
Figure 1
Explaining changes of state using the particle model
118
Unit B
Chemistry
NEL

ADVERTISEMENT

00 votes

Related Articles

Related forms

Related Categories

Parent category: Education
Go
Page of 2