Chapter 8
States of
Matter
•Objective:
•Describe three
states of matter.
•The states of
matter are the
physical forms in
which a substance
can exist.
•Matter is made up
of tiny particles
called atoms and
molecules.
•These particles are
always in motion
and are always
bumping into one
another
• There Are Three states of
matter:
• 1. A solid is the state of matter
that has a definite shape and
volume
• The particles in a solid do not
move fast enough to overcome
the attraction between them.
• Each particle vibrates in place
and is locked in place by the
There Are Two Kinds of
Solids:
• 1. Crystalline solids have a very
orderly, three-dimensional
arrangement of particles.
• 2. Amorphous solids are made
of particles that do not have a
special arrangement.
• 2. Liquid is the state of matter
that has a definite volume and
but takes the shape of its
container.
• The particles of a liquid move
fast enough to overcome some
of the attraction between them.
• So, the particles in a liquid slide
past each other.
Liquids have two special
properties:
• Surface tension is a force that
acts on the particles at the
surface of a liquid.
• Viscosity is a liquid’s resistance
to flow.
• 3. Gas is the state of matter that
has no definite shape or
volume.
• The particles of a gas move
quickly and can break away
completely from one another.
• The amount of empty space
between gas particles can
change.
• Objective: Describe
how energy is
involved in changes
of state.
• A change of state is the
change of a substance from
one physical form to another.
• Changes of State:
• 1. Solid to Liquid
• 2. Liquid to Solid
• 3. Liquid to Gas
• 4. Gas to Liquid
• 5. Solid to Gas
• 1. Melting is the change of state
from a solid to a liquid.
• The temperature a solid
changes to a liquid is its melting
point.
• Adding energy to a substance
during a change of state is
called an endothermic change.
• 2. Freezing is the change of
state from a liquid to a solid.
• The temperature a liquid
changes to a solid is its freezing
point.
• Removing energy to a
substance during a change of
state is called an exothermic
change.
• 3. Evaporation is the change of
state from a liquid to gas.
Evaporation occurs at the
surface of a liquid that is below
its boiling point.
• Boiling is the change of a liquid
to a gas throughout the liquid.
The temperature a liquid boils is
its boiling point.
• 4. Condensation is the
change of state from a gas to
a liquid. The condensation
point is the temperature a
gas becomes a liquid.
• 5. Sublimation is the change of
state where a solid changes
directly into a gas.
• Objective:
• Identify the two changes that
can happen when a
substance loses or gains
energy.
• When most substances lose
or gain energy, one of two
things happen to the
substance: temperature
changes or state changes.
• But the temperature of a
substance does not change
during the change of state.