Thermal Motion

the random motion of the microparticles, such as molecules, atoms, and electrons, that constitute all bodies. Thermal motion is a special kind of motion of matter and is qualitatively different from ordinary mechanical motion, in which all parts of a body move in an orderly manner. Brownian movement is the most convincing experimental proof of thermal motion. The regularities of thermal motion are studied by means of thermodynamics, statistical mechanics, and physical kinetics. The kinetic energy of thermal motion is directly proportional to absolute temperature and is a component of the internal energy of a physical system.