kT (also written as kBT) is the product of the Boltzmann constant, k (or kB), and the temperature, T.

What is the significance of kT?

It is represented by the letter k. If the temperature T is measured from absolute zero, the quantity kT has the dimensions of an energy and is usually called the thermal energy. At 300 K (room temperature), kT = 0.0259 eV.

What is k in Boltzmann constant?

Having dimensions of energy per degree of temperature, the Boltzmann constant has a defined value of 1.380649 × 10−23 joule per kelvin (K), or 1.380649 × 10−16 erg per kelvin.

The Boltzmann constant (kB or k) is the proportionality factor that relates the average relative kinetic energy of particles in a gas with the thermodynamic temperature of the gas.