3-1: Matter and Energy
Tuesday, August 18, 2015
5:45 PM
Key terms:
Plasma - a state of matter that starts as a gas and then becomes ionized.
Energy - the capacity to do work
Thermal energy - the (total) kinetic energy of a substance's atoms
Evaporation - the change of a substance from a liquid to a gas
Sublimation - the process in which a solid changes directly into a gas (the term is sometimes
used for the reverse process, too)
Condensation - the change of a substance from a gas to a liquid
I. Kinetic Theory
a. All matter is made of atoms and molecules that act like tiny particles.
b. These tiny particles are always in motion. The higher the temperature of the substance, the
faster the particles move.
c. At the same temperature, more-massive (heavier) particles move slower than less massive
(lighter) particles.
The states of matter are physically different. You're familiar with at least 3 states of matter--solid, liquid,
and gas. There are more!!! These 5 are the most common.
Less energy
Colder
Approaching absolute zero (0K)
More energy
Warmer
Bose-Einstein condensates
Some substances, as they approach absolute zero (0K), they begin to "clump" together.
There are no longer thousands of separate atoms. They all take on the same qualities and, for our
purposes, become one blob.
For more information: http://www.chem4kids.com/files/matter_becondensate.html>
Solids have a definite shape and volume.
The structure of a solid is rigid, and the particles have almost no freedom to change position.
Ch3 States of Matter Page 1
The structure of a solid is rigid, and the particles have almost no freedom to change position.
Two types:
i. Crystalline solids - orderly, repeating pattern
ii. Amorphous solids - molecules in no particular order/pattern
Liquids change shape, not volume.
The particles in a liquid move more rapidly than those in a solid--fast enough to overcome the
forces of attraction between them. This allows liquids to flow freely.
Gases are free to spread in all directions.
The particles of a gas move fast enough to break away from each other.
Plasma is the most common state of matter.
Matter that does not have a definite shape and in which the particles have broken apart.
II. Energy's Role
Energy is the ability to change or move matter.
A. Thermal energy is the total kinetic energy of a substance.
Kinetic energy is the energy of motion. Kinetic and "Kinect"
come from the same root. The "Kinect" uses your motion
to control the video game.
B. Temperature is a measure of the average kinetic energy.
Particles of matter are constantly moving, but they do
not all move at the same speed. The more kinetic energy
the particles have, the higher the temperature.
III. Energy and Changes of State
Changes of state are physical changes, because the substance's identity does not change.
If energy is added to a substance, its particles speed up.
If energy is removed, the particles slow down.
a. Changes of state that require energy:
i. Melting
ii. Boiling
iii. Evaporation
iv. Sublimation
b. Changes of state that release energy:
i. Freezing
ii. Condensation
iii. Sublimation/Deposition
Ch3 States of Matter Page 2
iii. Sublimation/Deposition
When a substance loses or gains energy, either its temperature changes or its state changes. The
temperature of a substance does not change during a change of state.
IV. Conservation of Mass and Energy
a. Law of conservation of mass - matter cannot be created nor can it be destroyed
The total mass before and after a reaction remains the same
b. Law of conservation of energy - energy cannot be created nor can it be destroyed
The total amount of energy in the universe stays the same. Energy just changes forms.
Quick Quiz:
1. According to the ____________ theory, all matter is made of particles that are in constant
___________.
2. The five states of matter we talked about are ____________ , ____________ , ____________ ,
____________ , ____________ .
3. The state of matter that changes shape, but not volume is ____________ .
4. The total kinetic energy of the particles of an object is ____________ .
5. ____________ is a measure of average kinetic energy.
Ch3 States of Matter Page 3
5. ____________ is a measure of average kinetic energy.
6. Condensation is a(n) ____________ change because it involves a ____________ of energy.
Ch3 States of Matter Page 4