This document defines and describes the main types of energy: mechanical (kinetic, potential), thermal, chemical, light, electrical, and nuclear. Kinetic energy depends on an object's mass and velocity, while potential energy depends on its position or state. Thermal energy increases with temperature and is the energy of moving particles. Chemical energy is stored in chemical bonds, like those in food and burning fuels. Light energy travels very fast, and electrical energy involves the movement of electrons, especially in metals. Nuclear energy comes from splitting atomic nuclei and is used in nuclear power and weapons, though it is difficult and dangerous.