What describes the physical behavior of an ideal gas?

The physical behavior of an ideal gas is described by the ideal gas law, which states that pressure (P), volume (V), and temperature (T) are related by the equation PV = nRT, where n is the number of moles and R is the ideal gas constant. Ideal gases are assumed to consist of a large number of small particles that are in constant, random motion, with no intermolecular forces acting between them except during elastic collisions. This means that an ideal gas will expand to fill its container, and its pressure increases with temperature and decreases with volume, assuming a constant amount of gas.