Definitions for Topic 3 - Thermal Physics: 3.1 - Thermal concepts 3.2 - Modelling a gas
Temperature
A measure of how hot or cold something it
A measure of the average kinetic energy of the particles in an object
Two objects at the same temperature are in thermal equilibrium
K=C+273
Internal energy of a substance
The sum of the potential energy and the random kinetic energy of the particles in the substance
Specific heat capacity
The energy required to raise the temperature of one kilogram of a material by one kelvin
Specific latent heat of fusion
The energy required to change the phase of one kilogram of a material from solid to liquid (melting)
Specific latent heat of vaporization
The energy required to change the phase of one kilogram of a material from liquid to gas (boiling)
Pressure
The perpendicular force applied on the surface of an object per unit area
Ideal gas model
To predict the macroscopic properties of a gas based on the movement of gas particles
Gas molecules are considered tiny, point-like
The volume of each molecule is negligible
Intermolecular forces between the particles are negligible
Only have kinetic energy
All collisions are elastic
Molar mass (mu)
Mass per mole
The Avogadro constant (NA)
The number of atoms of molecules in one mole of a substance
n=N/NA
n - number of moles of the substance
N- number of atoms. Molecules in the substance
Ideal gas
A gas that perfectly obeys the gas laws under all conditions