The Boltzmann constant is a fundamental physical constant that relates the average kinetic energy of particles in a gas to its temperature. It is denoted by the symbol k and has a value of approximately 1.38 \times 10^-23 \, \textJ/K . This constant plays a crucial role in statistical mechanics, which helps explain how macroscopic properties of materials arise from the behavior of microscopic particles. In the context of thermodynamics, the Boltzmann constant connects temperature, energy, and entropy, providing a bridge between the microscopic world of atoms and molecules and the macroscopic world we observe. It is named after the Austrian physicist Ludwig Boltzmann, who made significant contributions to the field of statistical mechanics in the 19th century.