Topic Menu

Cyber-chess a chess instruction site

The Maxwell-Boltzmann Distribution Graphs

A description of the statistical distribution of the energies of the molecules of a 'classical' gas was first proposed by the Scottish physicist James Clerk Maxwell in 1859. On the basis of probabilistic arguments the law gave the distribution of velocities among the molecules of a gas at a particular temperature.

Maxwell's finding was further worked upon by a German physicist, Ludwig Boltzmann, and in 1871 he extended the findings to express the distribution of energies among the molecules.

A Maxwell Boltzmann graph displays the number of molecules in a gas with a range of kinetic energies at a particular temperature

At a given temperature:

No particle has zero energy - but there are always some with very low energies.

Most particles have intermediate energies (displayed around the peak of the curve)

Few particles have very high energies (displayed on the right-hand side of the curve)

The average energy is not the same as the most probable energy Maxwell Boltzmann graph

Effect of Increasing the Temperature

Increasing the temperature of a gas will thus give the molecules more kinetic energy

The Maxwell Boltzmann graph maximum moves to the right and the peak lowers, as there now molecules with more kinetic energy than was possible at the lower temperature... but not more molecules!