Kinetic-Molecular Theory All particles are in constant motion. Explains properties of matter.
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.
Expansion No definite shape or volume Gases ‘expand’ to fit any ‘container’
Fluidity Density Gas particles easily flow past each other. Very low Particles are very far apart.
Compressibility Particles pushed together Decreases volume
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’
Temperature Measure of the energy (movement) of particles Units of Temperature Degrees Celsius (C) Kelvin (K) ºCelsius + 273 = Kelvin Lord Kelvin
Pressure (P) Force per unit area
Units of Pressure Millimeters of Mercury (mm of Hg) Torrs Atmospheres (atm) kiloPascals (kPa) Pounds per square inch (psi)
Measuring Pressure Barometer Measures atmospheric pressure Height of mercury depends on atmospheric pressure
Manometer Measures an enclosed gas.