1. Kinetic-Molecular Theory
All particles are in constant motion.
Explains properties
of matter.

2. Ideal Gas = follows K-M theory
5 Assumptions
1. Lots of tiny particles that are far apart
2. Elastic collisions = no loss of energy
3. Have kinetic energy (KE) – constant motion
4. No forces of attraction or repulsion between particles
5. Average KE depends on temp.

3. Expansion No definite shape or volume
Gases ‘expand’ to fit any ‘container’

4. Fluidity Density Gas particles easily flow past each other. Very low
Particles are very far apart.

5. Compressibility
Particles pushed together
Decreases volume

6. Diffusion Effusion Mixing of particles caused by random motion
Ex: perfume can be smelled across the room
Effusion
Gas particles pass through tiny openings
Ex: Helium balloon slowly ‘deflates’

7. Temperature Measure of the energy (movement) of particles
Units of Temperature
Degrees Celsius (C)
Kelvin (K)
ºCelsius = Kelvin
Lord Kelvin

8. Pressure (P)
Force per unit area

9. Units of Pressure Millimeters of Mercury (mm of Hg) Torrs
Atmospheres (atm)
kiloPascals (kPa)
Pounds per square inch
(psi)

10. Measuring Pressure Barometer Measures atmospheric pressure
Height of mercury
depends on atmospheric
pressure

11. Manometer
Measures an enclosed gas.