Heat Energy

Heat and Temperature Heat is the transfer of thermal energy from a warmer object to a cooler object. Thermal Energy is the total energy of all the particles in an object. Temperature is a measure of how hot or cold something is compared to a reference point.

Adding and Removing Heat Adding heat to or removing heat from a system may result in a temperature change and possibly a change of state. Solid, Liquid, Gas Energy is the ability to do work or cause change. State is the form in which matter exists.

Motion of Molecules Solid: Definite shape, definite volume. Closely packed arrangement of particles that vibrate. Liquid: Definite volume but no shape of its own. The particles are packed tightly but not as rigid as a solid. The particles are able to move around one another freely. Gas: Has neither a definite shape nor definite volume. The particles spread out and move around freely.

Change of State Melting Point: The temperature at which a solid melts. Boiling Point: The temperature at which liquid boils. Melting: From a solid to a liquid. Boiling: From a liquid to a gas. Evaporation: The process by which molecules at the surface of a liquid absorb enough energy to change to gaseous state. Condensation: A gas cools and condenses to a liquid.

Heat Flow Conduction: Transfers heat from one particle of matter to another within an object or between two objects. By direct contact. Convection: Heat transfer that occurs only in fluids, such as water and air. Radiation: The transfer of energy by electromagnetic waves. Is the only form of heat transfer that does not require matter.