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```					States of Matter

Physical Science
Mrs. Armstrong
Chapter 3     States of Matter

Section 1 Matter and Energy

Section 2 Fluids

Section 3 Behavior of Gases
Chapter 3        Section 1 Matter and Energy

Objectives
• Summarize the main points of the kinetic theory
of matter.
• Describe how temperature relates to kinetic
energy.
• Describe four common states of matter.
• List the different changes of state, and describe
how particles behave in each state.
• State the laws of conservation of mass and
conservation of energy, and explain how they
apply to changes of state.
Chapter 3   Section 1 Matter and Energy

Bellringer

The nine drawings below contain different
types and numbers of atoms and molecules.
From your knowledge of the different
classifications of matter, categorize the
drawings shown.
Chapter 3   Section 1 Matter and Energy

Bellringer, continued

1. Identify each
diagram as one
of more of the
following:
solid, liquid,
gas, atoms
only, molecules
only, atoms
and molecules.
Chapter 3           Section 1 Matter and Energy

Kinetic Theory
• Here are the main points of the kinetic theory
of matter:

• All matter is made of atoms and molecules that act like tiny
particles.

• These tiny particles are always in motion. The higher the
temperature of the substance, the faster the particles move.

• At the same temperature, more-massive (heavier) particles
more slower than less-massive (lighter) particles.
Chapter 3   Section 1 Matter and Energy

Kinetic Molecular Theory
Chapter 3        Section 1 Matter and Energy

Kinetic Theory, continued
• The states of matter differ physically from
one another.

• Particles of a solid, such as iron, are in fixed
positions.

• In a liquid, such as cooking oil, the particles are
closely packed, but they can slide past each other.

• Gas particles are in a constant state of motion
and rarely stick together.
Chapter 3     Section 1 Matter and Energy

States of Matter
Chapter 3   Section 1 Matter and Energy

Solid, Liquid, and Gas
Chapter 3        Section 1 Matter and Energy

Kinetic Theory, continued
• Solids have a definite shape and volume.

• The structure of a solid is rigid, and the particles
have almost no freedom to change position.

• Crystalline solids have an orderly arrangement of
atoms or molecules.

• Amorphous solids are composed of atoms or
molecules that are in no particular order.
Chapter 3   Section 1 Matter and Energy

Properties of Solids
Chapter 3          Section 1 Matter and Energy

Kinetic Theory, continued
• Liquids change shape, but not volume.

• The particles in a liquid move more rapidly than those of a
solid—fast enough to overcome the forces of attraction
between them.

• The particles in a liquid can slide past each other, flowing
freely. Liquids can take the shape of the container they are
put into.

• Liquids have surface tension, the force acting at the surface
of a liquid that causes a liquid, such as water, to form
spherical drops.
Chapter 3   Section 1 Matter and Energy

Liquid
Chapter 3   Section 1 Matter and Energy

Properties of Liquids
Chapter 3     Section 1 Matter and Energy

Kinetic Theory, continued
• Gases are free to spread in all directions.

• The particles of a gas move fast enough to break
away from each other.

• The space between gas particles can change, so a
gas expands to fill the available space.

• A gas can also be compressed to a
smaller volume.
Chapter 3   Section 1 Matter and Energy

Gas
Chapter 3       Section 1 Matter and Energy

Kinetic Theory, continued
• Plasma is the most common state of matter.
• Plasma is a state of matter that starts as a gas and
then becomes ionized.
• Plasmas conduct electric current, while gases
do not.
• Natural plasmas are found in lightning and fire.
The glow of a fluorescent light is caused by an
artificial plasma, created by passing electric
currents through gases.
Chapter 3        Section 1 Matter and Energy

Energy’s Role
• Energy is the capacity to do work.

• Sources of energy can include:

• electricity, candles, and batteries

• the food you eat

• chemical reactions that release heat
Chapter 3   Section 1 Matter and Energy

Energy
Chapter 3        Section 1 Matter and Energy

Energy’s Role, continued
• According to the kinetic theory, all matter is made
of particles that are constantly in motion.

• Because the particles are in motion, they have
kinetic energy, or energy of motion.

• Thermal energy is the total kinetic energy of a
substance.

• The more kinetic energy the particles in the object
have, the more thermal energy the object has.
Chapter 3      Section 1 Matter and Energy

Energy’s Role, continued
• Temperature is a measure of average kinetic
energy.

• Unlike total kinetic energy, temperature does not
depend on how much of the substance you have.

• For example, a teapot contains more tea than a
mug does, but the temperature, or average kinetic
energy of the particles in the tea, is the same in
both containers.
Chapter 3     Section 1 Matter and Energy

Energy and Changes of State
• A change of state—the conversion of a substance
from one physical form to another—is a
physical change.
• The identity of a substance does not change
during
a change of state, but the energy of a substance
does change.
• A transfer of energy known as heat causes the
temperature of a substance to change, which can
lead to a change of state.
Chapter 3     Section 1 Matter and Energy

States of Matter
Chapter 3       Section 1 Matter and Energy

Energy and Changes of State,
• Some changes ofcontinued energy.
state require

• Evaporation is the change of a substance from a
liquid to a gas. Energy is needed to separate the
particles of a liquid to form a gas.

• Sublimation is the process by which a solid turns
directly to a gas. Sometimes ice sublimes to form a
gas.
Chapter 3                           Section 1 Matter and Energy

Energy and Changes of State,                     continued

• Energy is released in some changes of state.
• Condensation is the change of a substance from a gas
to a liquid. Energy is released from the gas and the
particles slow down.
• Energy is also released during freezing, which is the
change of state from a liquid to a solid.

• When a substance loses or gains energy, either
its temperature changes or its state changes, but
not both.
Chapter 3        Section 1 Matter and Energy

Conservation of Mass and Energy
• The law of conservation of mass says that
mass cannot be created or destroyed.
• For instance, when you burn a match, the total
mass of the reactants (the match and oxygen) is
the same as the total mass of the products (the
ash, smoke, and gases).
• The law of conservation of energy states
that
energy cannot be created or destroyed.
• For instance, when you drive a car, gasoline
releases its stored energy, in the form of heat,
used to move the car.
Chapter 3   Section 1 Matter and Energy

Law of Conservation of Mass
Chapter 3   Section 1 Matter and Energy

Law of Conservation of Energy
Chapter 3        Section 2 Fluids

Objectives
• Describe the buoyant force and explain how it
keeps
objects afloat.

• Define Archimedes’ principle.

• Explain the role of density in an object’s ability to
float.

• State and apply Pascal’s principle.

• State and apply Bernoulli’s principle.
Chapter 3             Section 2 Fluids

Bellringer
Although you may not be familiar with the specific details, you
have seen buoyant forces at work. You know from experience that
certain objects float in air or in water. This is because of the force
that pushes, or buoys the object up. This force opposes the weight
of the object, which is always in the downward direction.
Examine each of the drawings shown on the next slide. Then
Chapter 3                 Section 2 Fluids

Bellringer, continued

1. Is the buoyant force on the lump of gold greater than, less than, or equal
to the gold’s weight?
2. Is the buoyant force on the balloon greater than, less than, or equal to the
balloon’s weight?
3. Is the buoyant force on the boat greater than, less than, or equal to the
boat’s weight?
4. Is the buoyant force on the submarine greater than, less than, or equal to
the submarine’s weight?
Chapter 3      Section 2 Fluids

Fluids
• A fluid is a nonsolid state of matter in which the
atoms or molecules are free to move past each
other, as in a gas or liquid.
• Fluids are able to flow because their particles can
move past each other easily.
• The properties of fluids allow huge ships to float,
divers to explore the ocean depths, and jumbo
jets
to soar across the skies.
Chapter 3   Section 2 Fluids

Fluid
Chapter 3      Section 2 Fluids

Buoyant Force
• Buoyant force is the upward force exerted on
an object immersed in or floating on a fluid.
• Buoyancy explains why objects float.
• All fluids exert pressure: the amount of force
exerted per unit area of a surface.
• Archimedes’ principle states that the buoyant
force on an object in a fluid is an upward force
equal to the weight of the volume of fluid that the
object displaces.
Chapter 3      Section 2 Fluids

Buoyant Force, continued
• The volume of fluid displaced by an object
placed in a fluid will be equal to the volume of
the part of the object submerged.

• The figure below shows how displacement
works.
Chapter 3       Section 2 Fluids

Buoyant Force, continued
• An object will float or sink based on its
density.

• If an object is less dense than the fluid in which it
is placed, it will float.

• If an object is more dense than the fluid in which
it is placed, it will sink.
Chapter 3   Section 2 Fluids

Density
Chapter 3     Section 2 Fluids

Fluids and Pressure
• Fluids exert pressure evenly in all directions.

• For example, when you pump up a bicycle tire, air
particles are constantly pushing against each
other and against the walls of the tire.
Chapter 3         Section 2 Fluids

Fluids and Pressure, continued
• Pressure can be calculated by dividing force by
the area over which the force is exerted:
force
pressure 
area

• The SI unit for pressure is the pascal (abbreviation: Pa),
equal to the force of one newton exerted over an area of
one square meter (1 N/m2).
Chapter 3      Section 2 Fluids

Pascal’s Principle
• Pascal’s principle states that a fluid in
equilibrium contained in a vessel exerts a
pressure of equal intensity in all directions.

• Mathematically, Pascal’s principle is stated as
p1 = p2, or pressure1 = pressure2.
Chapter 3                         Section 2 Fluids

Math Skills
Pascal’s Principle A hydraulic lift, shown in the figure
below, makes use of Pascal’s principle, to lift a 19,000
N car. If the area of the small piston (A1) equals 10.5
cm2 and the area of the large piston (A2) equals 400
cm2, what force needs to be exerted on the small
piston to lift the car?
Chapter 3     Section 2 Fluids

Math Skills, continued
1. List the given and unknown values.
Given:      F2 = 19,000 N
A1 = 10.5 cm2
A2 = 400 cm2
Unknown: F1

2. Write the equation for Pascal’s principle.
According to Pascal’s principle, p1 = p2.
F1 F2             (F2 )( A1 )
          F1 
A1 A2                A2
Chapter 3        Section 2 Fluids

Math Skills, continued
3. Insert the known values into the equation,
and solve.

(19,000 N)(10.5 cm2 )
F1 
400 cm2
F1 = 500 N
Chapter 3                        Section 2 Fluids

Pascal’s Principle, continued
• Hydraulic devices are based on Pascal’s
principle.
• Hydraulic devices can multiply forces, as shown in
the figure below. Because the pressure is the
same on both sides of the enclosed fluid, a small
force on the smaller area (at left) produces a
much larger force on the larger area (at right).
Chapter 3                          Section 2 Fluids

Fluids in Motion
• Viscosity is the resistance of a gas or liquid to
flow.
• Bernoulli’s principle states that as the speed
of a moving fluid increases, the pressure of
the moving fluid decreases.
• Bernoulli’s principle is illustrated below: as a leaf
passes through a drainage pipe from point 1 to
point 2, it speeds up, and the water pressure
decreases.
Chapter 3      Section 3 Behavior of Gases

Objectives

• Explain how gases differ from solids and
liquids.

• State and explain the following gas laws:
Boyle’s law, Charles’s law, and Gay-Lussac’s
law.

• Describe the relationship between gas
pressure, temperature and volume.
Chapter 3             Section 3 Behavior of Gases

Bellringer
The pressure of gas depends on how frequently the particles of gas strike
the sides of the container holding the gas. Use your experience and, after
examining each of the pairs of drawings shown below, decide whether
you think the pressure of the contained gas has increased, decreased, or
remained unchanged.

1. The gas in the cylinder of an automatic engine undergoes the change
shown below. Does the pressure of the gas
a. increase?
b. decrease?
c. remain unchanged?
Chapter 3            Section 3 Behavior of Gases

Bellringer, continued
2. The gas in the toy balloon expands outward, as shown below. After this
expansion, has the pressure of the gas
a. increased?
b. decreased?
c. remained unchanged?

3. The temperature of the water vapor in the pressure cooker increases.
Does the pressure of the gas
a. increase?
b. decrease?
c. remain unchanged?
Chapter 3       Section 3 Behavior of Gases

Properties of Gases
• Gases have unique properties. Some
important properties of gases are listed below.
• Gases have no definite shape or volume, and they
expand to completely fill their container.

• Gas particles move rapidly in all directions.

• Gases spread out easily and mix with one another.
Unlike solids and liquids, gases are mostly empty
space.
Chapter 3          Section 3 Behavior of Gases

Properties of Gases, continued
• (some important gas properties, continued)
• Gases have a very low density because their particles
are so far apart. Because of this property, gases are
used to inflate tires and balloons.
• Gases are compressible.
• Gases are fluids.
• Gas molecules are in constant motion, and they
frequently collide with one another and with the walls
of their container.
Chapter 3                                Section 3 Behavior of Gases

Properties of Gases, continued

• Gases exert pressure on their containers.

• The kinetic theory helps to explain pressure. Helium atoms in a
balloon are constantly hitting each other and the walls of the
balloon, as shown below.

• Therefore, if the balloon is punctured, the gas will escape with a
lot of force, causing the balloon to pop.
Chapter 3      Section 3 Behavior of Gases

Gas Laws
• Boyle’s law states that for a fixed amount of
gas at a constant temperature, the volume of
the gas increases its pressure decreases.
Likewise, the volume of a gas decreases as its
pressure increases.

• Boyle’s law can be expressed mathematically as:
(pressure1)(volume1) = (pressure2)(volume2) ,
or P1V1 = P2V2
Chapter 3   Section 3 Behavior of Gases

Boyle’s Law
Chapter 3      Section 3 Behavior of Gases

Math Skills
Boyle’s Law The gas in a balloon has a volume of
7.5 L at 100 kPa. The balloon is released into the
atmosphere, and the gas expands to a volume of
11 L. Assuming a constant temperature, what is
the pressure on the balloon at the new volume?
1. List the given and unknown values.
Given: V1 = 7.5 L
P1 = 100 kPa
V2 = 11 L
Unknown:        P2
Chapter 3                     Section 3 Behavior of Gases

Math Skills, continued
2. Write the equation for Boyle’s law, and
rearrange the equation to solve for P2.
P1V1 = P2V2
PV1
P2  1
V2

3. Insert the known values into the equation,
and solve.
(100 kPa)(7.5 L)
P2 
11 L
P2 = 68 kPa
Chapter 3                        Section 3 Behavior of Gases

Gas Laws, continued
• Charles’s law states that for a fixed amount of
gas at a constant pressure, the volume of the
gas increases as its temperature decreases.
Likewise, the volume of a gas decreases as its
temperature increases.

• As shown below, if the gas in an inflated balloon is
cooled (at constant pressure), the gas will decrease
in volume and cause the balloon to deflate.
Chapter 3    Section 3 Behavior of Gases

Charles’s Law
Chapter 3                         Section 3 Behavior of Gases

Gas Laws, continued
• 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.

• This is why, if a pressurized container that holds
gas, such as a spray can, is heated, it may explode.
Chapter 3      Section 3 Behavior of Gases

Concept Mapping
Chapter 3      Standardized Test Prep

Understanding Concepts
1. Which of the following changes of state is
exothermic?

A. evaporation
B. freezing
C. melting
D. sublimation
Chapter 3      Standardized Test Prep

Understanding Concepts
1. Which of the following changes of state is
exothermic?

A. evaporation
B. freezing
C. melting
D. sublimation
Chapter 3     Standardized Test Prep

Understanding Concepts
2. Which of these statements describes the
particles of a liquid?

F. Particles are far apart and move freely.
G. Particles are close together and vibrate in
place.
H. Particles are far apart and unable to change
location.
I. Particles are close together and move past
each other easily.
Chapter 3     Standardized Test Prep

Understanding Concepts
2. Which of these statements describes the
particles of a liquid?

F. Particles are far apart and move freely.
G. Particles are close together and vibrate in
place.
H. Particles are far apart and unable to change
location.
I. Particles are close together and move past
each     other easily.
Chapter 3     Standardized Test Prep

Understanding Concepts
3. As the plunger is depressed, the volume of a
syringe filled with helium gas is reduced from
25 mL to 10 mL. If the initial pressure is 150
kPa, what is the final pressure, in kPa,
assuming constant temperature?
Chapter 3     Standardized Test Prep

Understanding Concepts
3. As the plunger is depressed, the volume of a
syringe filled with helium gas is reduced from
25 mL to 10 mL. If the initial pressure is 150
kPa, what is the final pressure, in kPa,
assuming constant temperature?

Chapter 3      Standardized Test Prep

If the temperature in a citrus orchard drops
below
–2°C for several hours, the fruit will freeze and
be destroyed. Citrus growers spray tiny droplets
of water to protect the crop if a freeze is
predicted. Protection comes from the heat
released as the heated water cools. However,
much of the heat that protects trees from
freezing is released as the water freezes.
Chapter 3      Standardized Test Prep

4. Based on the energy changes that occur
when materials change state, determine how
water freezing on the fruit can protect it from
becoming too cold?
Chapter 3      Standardized Test Prep

4. Based on the energy changes that occur
when materials change state, determine how
water freezing on the fruit can protect it from
becoming too cold?

Answer: The process of freezing is exothermic,
so heat is generated as water changes from
the liquid to the solid state. This heat protects
the tree as the water freezes on it.
Chapter 3    Standardized Test Prep

Interpreting Graphics
the graph below.
Chapter 3     Standardized Test Prep

Interpreting Graphics
5. What is the boiling point of the substance
shown on the graph?

A. 20°C
B. Between 20°C and 80°C
C. 80°C
D. Above 80°C
Chapter 3     Standardized Test Prep

Interpreting Graphics
5. What is the boiling point of the substance
shown on the graph?

A. 20°C
B. Between 20°C and 80°C
C. 80°C
D. Above 80°C
Chapter 3      Standardized Test Prep

Interpreting Graphics
6. In what state is the substance at a
temperature of 30°C?

F. gas and liquid mix
G. liquid
H. solid
I. solid and liquid mix
Chapter 3      Standardized Test Prep

Interpreting Graphics
6. In what state is the substance at a
temperature of 30°C?

F. gas and liquid mix
G. liquid
H. solid
I. solid and liquid mix
Chapter 3     Standardized Test Prep

Interpreting Graphics
7. How will the substance change if energy is
added to the liquid substance at 20°C?

A. The liquid will freeze.
B. The liquid will vaporize.
C. The liquid will become warmer.
D. The liquid will not undergo any change.
Chapter 3     Standardized Test Prep

Interpreting Graphics
7. How will the substance change if energy is
added to the liquid substance at 20°C?

A. The liquid will freeze.
B. The liquid will vaporize.
C. The liquid will become warmer.
D. The liquid will not undergo any change.
Chapter 3     Standardized Test Prep

Interpreting Graphics
8. What occurs to the substance as energy is
added to the liquid at 80°C?

F. The liquid will freeze.
G. The liquid will vaporize.
H. The liquid will become warmer.
I. The liquid will not undergo any change.
Chapter 3     Standardized Test Prep

Interpreting Graphics
8. What occurs to the substance as energy is
added to the liquid at 80°C?

F. The liquid will freeze.
G. The liquid will vaporize.
H. The liquid will become warmer.
I. The liquid will not undergo any change.

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