Kinetic Theory of Gases

1.38 × 10⁻²³ J K⁻¹

Boltzmann constant \( k = \frac{R}{N_A} = 1.38 \times 10^{-23} \, \mathrm{J \, K^{-1}} \), where R is gas constant and \( N_A \) is Avogadro’s number.

Absolute temperature

The average kinetic energy of a gas molecule is \( \frac{3}{2} kT \), which depends only on absolute temperature T and not on mass, pressure, or volume.

Collisions are perfectly elastic

One of the key assumptions of kinetic theory is that molecules undergo perfectly elastic collisions with each other and with the walls of the container.

Cubical

For simplicity, a cubical container is assumed in the derivation of pressure, though the final result is independent of shape.