Weblink 1.6 The Boltzmann distribution

The Boltzmann distribution predicts that the (thermal) population of an energy level depends on its energy and the temperature. In this applet you can alter the temperature with the left-hand slider, and the spacing of the energy levels with the right-hand slider. The populations of the energy levels (shown in blue) are indicated by the yellow bars.

An important quantity is the energy k_BT, where k_B is Boltzmann's constant and T is the temperature. The value of this energy is shown by the red line. Only levels whose energies are less than or comparable to k_BT are populated. The dial at the top right shows the ratio of the energy level spacing to k_BT (on a log scale). The energy and entropy of the system are represented by the red and green bars respectively.