Topic 3 - Thermal Physics

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