Three States of Matter
Chapter 3 Section 1
Particles of Matter
• The states of matter are the physical forms in
which a substance can exist.
• The three most familiar states are solid, liquid,
and gas. (Plasma is the 4th state.)
• Matter is made of tiny particles called atoms and
molecules which are always in motion.
• The way these particles interact helps determine
the state of the matter.
Figure 1, Page 66
• Figure 1 on page 66 describes the three familiar states of
matter in terms of the speed and attraction of the particles.
• Solids – molecules are highly attracted to each
other and vibrate
• Liquids – molecules are close and slide past each
other
• Gas – little attraction because a lot of motion
Solids
• Solid – the state in which the substance has
a definite shape and volume
• The attraction between particles is stronger
than the particles of the same substance in
the liquid or gaseous state.
• Particles in a solid move, but only vibrate
in their place.
Types of Solids
• Crystalline solid – have a very orderly, 3-D
arrangement of particles; particles repeat in
a pattern
• Examples of crystalline solids are iron, diamond, and ice.
• Amorphous solid – particles do not have a
particular arrangement; substance can
change shape under certain conditions
• Examples of amorphous solids are glass, rubber, and wax.
Liquids
• Liquid – the state in which the substance
has a definite volume but no definite shape
• Particles move fast enough to overcome
some of the attraction between them.
• Molecules slide past each other to take the
shape of the container.
• The shape of a liquid can change, but the
volume cannot.
Characteristics of Liquids
• Surface Tension – a force that acts on the
particles at the surface of a liquid
• Surface tension causes some liquids to form
spherical drops and is different in different types
of liquids.
• Viscosity – a liquid’s resistance to flow
• The stronger the attraction between the molecules
of a liquid, the more viscous the liquid is.
Gases
• Gas – the state of matter that has no
definite shape or volume.
• Particles of a gas move quickly so there is
less attraction between the particles.
• The amount of empty space between gas
particles can change depending on the
container the gas is in.
Behavior of Gases
Chapter 3 Section 2
Temperature
• Temperature is a measure of how fast the
particles in an object are moving.
• The faster the particles are moving the more
energy they have.
• On a hot day, gas particles move faster
than on a cold day. Therefore, there is
more pressure on the walls of the container
holding the gas when the temperature is
high.
Temperature
• Less gas is needed to fill a balloon in warm
temperatures because the particles of the
gas have more energy.
• At cool temperatures particles move
slower.
• To fill a balloon in cool temperatures more
gas is needed because the particles of the
gas have less energy.
Temperature
• As external temperatures increase, the
gases in a balloon expand and the balloon
could pop.
• When external temperatures decrease, the
gases in a balloon condense and the
balloon shrinks.
Volume
• Volume is the amount of space an object
takes up.
• Particles of gas spread out, so the volume
of a gas depends on the container the gas is
in.
• Intro to PVT gases
Pressure
• The amount of force exerted on a given
area of surface is pressure.
• The basketball and beach ball in Figure 2
on page 71 hold the same volume of air.
• There are more particles inside the
basketball colliding with the inside surface
of the ball.
• There is more pressure in the basketball.
Gas Behavior Laws
• The temperature, pressure, and volume of a
gas are linked.
• Changing one of these factors will change
the other two.
• Gas laws describe the relationships
between temperature, pressure, and
volume.
Boyle’s Law
• Boyle’s Law states that for a fixed amount
of gas at a constant temperature, the
volume of the gas is inversely related to
pressure.
• As the pressure of a gas increases, the
volume decreases by the same amount.
Charles’s Law
• Charles’s Law states that for a fixed amount of
gas at a constant pressure, the volume of the gas
changes in the same ways that the temperature of
the gas changes.
• Decreasing the temperature of the gas causes the
volume of the gas to decrease.
• Increasing the temperature of the gas causes the
volume of the gas to increase.