States of Matter
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Matter is anything that has mass (weight) and takes up space.

Air has a weight of 15 pounds
per square inch at sea level. A 
barometer is an instrument that
measures air pressure.
4 States of Matter
The motion of molecules and the
strength of the attraction between
them determine the state.
SOLIDS have a definite
shape and volume.

Atoms in a solid are packed
close together and vibrate in
place.
Most solids form CRYSTALS.
Crystals are formed when 
the atoms or molecules of
a solid occur in a repeating
3-dimensional pattern. These
are salt crystals.
AMORPHOUS SOLIDS do not form
crystals. Solids such as plastic, glass, 
and rubber are amorphous. Their 
particles are not arranged in a repeating
pattern.
Which one of these
is an amorphous solid?
LIQUIDS have a definite
volume but not a definite
shape.

Particles (atoms or molecules)
in liquids are close together
but are free to move around.
VISCOSITY is a property of liquids. 
It is the resistance to flow. Liquids 
with a high viscosity flow very slowly.
SURFACE TENSION is another property
of liquids. Molecules on the surface of a
liquid attract each other so they pull 
themselves tight, forming a very thin film
on the surface.

GAS is matter that does not
have a definite volume or shape.
It takes the shape and size of the
container it is in. Gas molecules 
move about freely.

Air is a mixture of gases. Most
gases are invisible.
VAPOR is gas occurring at a
temperature where the substance
is usually liquid or solid. Water
vapor, for example, is gaseous
water at room temperature.
Can you find all 4 states of
matter in this photograph?
PLASMA is the state of
matter that is like a gas
but is made of electrically-
charged particles and is
very hot.
The glowing streamers are made of plasma.
The sun and other stars are made
of plasma. Plasma occurs inside
neon lights and in the tiny pixels 
of a plasma TV screen.
Surface tension makes it possible to float
a pin on water. Some insects make use of
surface tension, too.
Matter does not have to be
visible. Air is matter because
it takes up space and has mass.
Solids
liquids
gases
plasma
Matter:
Bricks
Tables
Chairs
Air
Water
Not Matter:
Emotions
Temperature
Energy
Words
Air contains the gases
nitrogen, oxygen, water
vapor, carbon dioxide, 
and argon.