1. Chapter 3 States of Matter 3.1 Matter and Energy
Pennsylvania Standards for Science and Technology A-D

2. Focus Activity
Why do you think you can smell fresh cut grass on a summer day when you are several meters away, 0r smell scents of food cooking if you are a few rooms away.

3. Objectives
As a result of what we do in class today, you will be able to:
Summarize the three main points of the kinetic theory of matter
Describe how temperature relates to kinetic energy
Describe the four common states of matter
List and describe the changes of state of matter and describe particle motion
State the law of conservation of mass, and energy and how they apply to change of state

4. Kinetic Theory
All matter is made up of atoms and molecules that act as tiny particles
These particles are always in motion,
the higher the temperature the faster
they move
At the same temperature more
massive (heavier) particles move
slower than less massive(lighter)
particles

5. States of Matter
The Kinetic Theory of Matter allows us to understand the differences among the common states of matter; solids, liquids, and gases
States of matter are physically different
The major differences are the distances
between the individual atoms or molecules
and how how closely the particles are
packed together

6. States of Matter Solids have a definite shape and volume
- the structure is rigid
- particles held together closely by
strong attractions – they have no
freedom to change position
- but they still move – they vibrate.

7. States of Matter Solids exist in one of two forms Crystalline solids
- orderly arrangement of atoms
- Ex: iron, diamond, ice
Amorphous Solid
- atoms are arranged in no particular order
- Ex: rubber, wax, gum, etc.

9. States of Matter (cont)
Liquids change shape but not volume
particles move faster than in solids
- they can overcome the forces of attraction
between them
they are free flowing and therefore they
can take the shape of their container
- but, they can’t change volume
Surface tension- force acting on particles at
the surface of a liquid
- causes a liquid to form spherical drops

10. States of Matter (cont)
Gases are free to spread in all directions
- particles move fast enough to break away
from each other
- gases expand to fill the available space
- therefore they have no definite shape or volume

11. States of Matter (cont)
Plasma most common state of matter
99% of all known matter in the universe
(the sun and all other stars)
- does not have a definite shape
- similar to gases, but different
conduct electricity – gases do not
affected by magnetism – gases are not
natural plasmas are found in lightening, fire,
and the aurora borealis
artificial plasmas are found in fluorescent lights

14. Energy’s Role
Energy is all around us, and we use it for just about everything.
Recall energy is the capacity to do work!
Energy also gives us the ability to
change and move matter
The Kinetic Theory of Matter states that
all particles are in motion
There is kinetic energy involved

15. Energy’s Role
Thermal energy- is the total kinetic energy of the particles that make up the object
The more kinetic energy, the more
thermal energy
Also depends on the number of
particles in a substance

16. Temperature Temperature is the measure of the
average kinetic energy of a substance
The more kinetic energy higher
temperature (the faster the particles
are moving)
Two objects at the same temperature
can have different amounts of kinetic
energy
- more mass (more particles)

17. Changes of State
A change in state – conversion from one physical form to another – is a physical change
- the identity of the substance doesn’t change, but its energy does
If energy is added, the particles move faster – If energy is removed, the particles move slower
The transfer of energy, known as heat, causes the temperature to change and can cause a change in state

18. Changes of State
Sensible Heat is the heat gained or lost by a substance which can be measured by a change in temperature
Latent Heat is the heat that a substance gains or loses as it changes phase
- This extra heat is necessary to break down or form the orderly arrangement of particles necessary to change from one state to another
- There is no change in temperature

19. Changes of State
Endothermic change - changes of state that require the addition of energy.
Heating a solid transfers energy to atoms
and breaks them from fixed position
Melting is the change from a solid
to a liquid state

20. Changes of State
Evaporation- change from liquid to a gas, energy is gained and separation from liquid to a gas occurs
Ex: Boiling water
Sublimation- solid changes directly
to a gas
Ex: Dry Ice – no liquid state

22. Changes of State (cont)
Exothermic change- Energy is released in some changes of state
Condensation- change of state from a gas
to a liquid, molecules slow down and combine
Freezing- change from liquid to solid,
molecule speed slows down, particles clump
together into fixed positions

25. Conservation of Mass and Energy
Mass cannot be created or destroyed
EX: Striking a match
Energy cannot be created or
destroyed
Energy may seem to go away when a change in state
occurs, but it just changes into another form

26. Conservation of Energy in a Chemical Reaction
surroundings
surroundings
Energy
system
system
Before
Reaction
After
Reaction