Chapter 3: States of Matter
SECTION 1: MATTER AND ENERGY
SECTION 2: FLUIDS
SECTION 3: BEHAVIOR OF GASES
Section 1: Matter and Energy
Key Terms
Plasma
Energy
Thermal Energy
Evaporation
Sublimation
Condensation
Section 1: Matter and Energy
Kinetic Energy
* All matter is made up of atoms and molecules that
act like tiny particles
* These tiny particles are always in motion. (High
temp. equals faster movement)
* At the same temp, more massive particles move
slower then less massive particles.
Section 1: Matter and Energy
The states of matter are physically different
Solids - particles are in a fixed position
Liquids - closely packed, but they can still slide past
each other
Gases - particles are in a constant state of motion
Section 1: Matter and Energy
Solids have a definite shape and volume
Solids do not need a container to keep its shape
Particles in solids have almost no freedom to change
position, but they vibrate.
Section 1: Matter and Energy
Solids are divided into two categories
1. Crystalline - have an orderly arrangement of atoms
or molecules
(Ex. Iron, diamonds, and ice)
2. Amorphous - composed of atoms or molecules
that are in no particular order. Each particle is in a
particular place, but the particles are not in an
organized pattern.
(Ex. Wax and rubber)
Section 1: Matter and Energy
Liquids change shape, not volume
Liquids have a definite volume, but change shape.
Particles in a liquid move fast enough to over come the
forces of attraction between them.
Section 1: Matter and Energy
Besides volume, another property of a liquid is
surface tension.
Surface tension is the force acting on the
particles at the surface of a liquid that cause a
liquid, such as water, to form spherical drops.
Gases are free to spread in all directions
Gases expand to fill the available space. They
change both shape and volume.
Section 1: Matter and Energy
When gases are placed into a bottle, they are forced
together. Once thy are released, they fill the
available space.
Plasma is the most common states of matter.
Scientist estimate that 99% of the known matter is
made up of plasma
Section 1: Matter and Energy
Plasma is the state of matter that does not have a
definite shape and in which the particles have broken
apart.
Plasma also conducts electric currents
Natural plasmas are found in lighting, fire, and aurora
borealis.
Section 1: Matter and Energy
How is the glow of fluorescent lights
caused?
By artificial plasma, which is formed by
passing electric currents through gases.
Section 1: Matter and Energy
Energy’s Role
Energy is the capacity to do work
Thermal energy is the total kinetic energy of a
substance
All matter is made up of particles (atoms and
molecules) that are in constant motion
Section 1: Matter and Energy
Thermal energy is the kinetic energy of a substance’s
atoms
At higher temperatures, particles of matter move
faster. The more kinetic energy the greater the
objects thermal energy.
Thermal energy also depends on the number of
particles in a substance.
Section 1: Matter and Energy
Temperature is a measure of average kinetic energy
The more kinetic energy the higher the energy
Since particles of matter are in constant motion, and
not all particles are moving at the same speed, you
measure the average kinetic energy.
Section 1: Matter and Energy
Energy and Change of State
A change of state is the conversion of a substance from
one physical form to another.
When we talk about change of state, the substance
does not change only the energy changes.
Section 1: Matter and Energy
Increase energy the particles move faster
Decrease energy the particles move slower
The temperature of a substance is a measure of energy
Solid  Liquid  Gas
Section 1: Matter and Energy
Solid to Liquid
Liquid to Gas
Gas to Liquid
Liquid to Solid
Solid to Gas
= Melting
= Evaporation
= Condensation
= Freezing
= Sublimation
Section 1: Matter and Energy
Some changes of state require energy
Changes that require energy are called
endothermic changes.
Evaporation is the change of a substance from
a liquid to a gas
Section 1: Matter and Energy
Boiling point is the temperature at which
a liquid changes to a gas and is a
characteristic property
Solids can also change to gases this is
called sublimation.
Section 1: Matter and Energy
Energy is released in some change of state
Changes that release energy are called
exothermic changes
When water freezes or a gas becomes a liquid
are examples of releasing energy
Condensation is the change of a substance
from a gas to a liquid.
Section 1: Matter and Energy
Temperature change verses change in
state
Temperatures do not change during a
state of change.
Section 1: Matter and Energy
Conservation of Mass and Energy
Mass cannot be created or destroyed
Both in a chemical or a physical change, the
total mass of matter stays the same before
and after the change.
Section 1: Matter and Energy
Matter changes but the total mass stays the
same.
Energy cannot be created or destroyed.
Energy may be converted to another form
during a physical or chemical change, but
the total amount of energy present before
and after the change is the same.
Section 2: Fluids
Key Terms
Fluid
Pascal’s Principle
Buoyant Force
Viscosity
Pressure
Archimedes’ Principle
Pascal
Section 2: Fluids
Fluids
Since both liquids and gases have the ability
to flow they are referred to as fluids.
Fluids are able to flow because their particles
can move past each other easily
Section 2: Fluids
Buoyant Force
Is the upward force that fluids exert on
matter
What determines if something will float or
sink?
Density and the buoyant force
Section 2: Fluids
Buoyancy explains why objects float
All fluids exert pressure, which is the
amount of force exerted on a given area
Pressure of all fluids increase as the depth
increases
Section 2: Fluids
Determining Buoyant Force
Archimedes’ principle states that buoyant
force on an object in a fluid is an upward
force equal to the weight of the fluid that the
object displaces.
Section 2: Fluids
An object will float or sink based on its
density
Since steel is almost eight times denser than
water how do ships float?
Ships float because of their hollow shape.
Remember that density equals mass
divided by volume.
Section 2: Fluids
Fluids and Pressure
Pressure is the amount of force exerted per
unit area of a surface. The SI unit for
pressure is Pascal (Pa)
Pressure is calculated by dividing force by the
area.
Pressure = force/area (1 Newton/m2)
Section 2: Fluids
Fluids exert pressure evenly in all directions.
Pascal’s principle states that a change in pressure
at any point in an enclosed fluid will be
transmitted equally to all parts of the fluid
Hydraulic devices are based on Pascal’s principle.
These devices use liquids to transmit pressure
from one point to another.
Section 2: Fluids
Why are liquids used instead of gases?
Because liquids cannot be compressed or
squeezed into a smaller place. Liquids
transmit pressure more efficiently.
Section 2: Fluids
Fluids in Motion
Fluids move faster through smaller areas
than through larger areas, if the overall flow
rate remains constant
Viscosity is resistance to flow
Section 2: Fluids
Fluid pressure decrease as speed increases
Bernoulli’s principle states that as the speed
of a moving fluid increases, the pressure of
the moving fluid decreases.
Section 3: Behavior of Gases
Key Terms
Boyle’s Law
Charles’ Law
Gay-Lussac’s Law
Section 3: Behavior of Gases
Behavior of Gases
Gases are often forgotten because they
are colorless and odorless. However,
gases are very important
Section 3: Behavior of Gases
Properties of Gases
No definite shape or volume
Particles move rapidly in all directions
Fluids
Molecules are in constant motion, and they frequently collide
with one another and with the walls of their container
Low density
Compressible
Spread out easily and mix with one another. Mostly empty
space
Section 3: Behavior of Gases
Gases exert pressure on their containers
Gas under pressure will escape its
container if possible
Section 3: Behavior of Gases
Gas Laws
The volume of a gas is the same as the volume
of its container but there are other factors,
such as pressure, to consider
The gas law describes how the behavior of
gases are affected by pressure and
temperature
Section 3: Behavior of Gases
Boyle’s Law relates the pressure of a gas to its
volume
Boyle’s Law states that for a fixed amount of
gas at a constant temperature, the volume of
a gas increases as its pressure decreases, or
the volume of a gas decreases as its pressure
increases
Section 3: Behavior of Gases
Boyle’s Law
Pressure  Volume 
Pressure  Volume 
Section 3: Behavior of Gases
Charles’ Law relates the temperature of a gas
to its volume
Charles’ Law states that for a fixed amount
of gas at a constant pressure, the volume of
gas increase as its temperature increases
and the volume of a gas decreases as its
temperature decreases
Section 3: Behavior of Gases
Charles’ Law
Temperature  Volume 
Temperature  Volume 
Section 3: Behavior of Gases
Gay-Lussac’s Law relates gas pressure to
temperature
As temperature increases, the kinetic energy
of the gas particles increase
Gay-Lussac’s Law states that the pressure of a
gas increases as the temperature increases if
the volume of the gas does not change
Section 3: Behavior of Gases
What does this mean?
If a pressurized container that holds gas
is heated it may explode.