Question

Distinguish between classical gas and a photon gas at normal temperature.

Answer 1

ThermodynamicsThe classical Carnot heat engineBranches[show]Laws[show]Systems[show]System properties[show]Material properties[show]Equations[show]Potentials[show]HistoryCulture[show]Scientists[show]Book:Thermodynamicsvte

An ideal gas is a theoretical gas composed of many randomly moving point particles whose only interactions are perfectly elastic collisions. The ideal gas concept is useful because it obeys the ideal gas law, a simplified equation of state, and is amenable to analysis under statistical mechanics. 

whereas,

Photon gas. In physics, a photon gas is a gas-like collection of photons, which has many of the same properties of a conventional gas like hydrogen or neon – including pressure, temperature, and entropy. The most common example of a photon gas in equilibrium is black body radiation.