Change in Energy Every chemical and physical change in matter includes a change in energy. Like matter, energy is conserved in a chemical change. Energy is never created or destroyed. It can only be transformed from one form to another.

Temperature vs. Thermal Energy Temperature is a measure of how hot or cold something is. Thermal Energy is the total energy of the motion of all the particles in an object. Thermal energy naturally flows from warmer matter to colder matter.

Thermal Energy: Two Types of Changes Thermal energy is a form of energy that is often released or absorbed when matter changes. Two types of changes: 1) Endothermic 2) Exothermic

Endothermic Change The melting of ice is an endothermic change, a change in which energy is absorbed. Ice absorbs thermal energy from its surroundings when it melts, leaving the surroundings feeling colder.

Exothermic Change Changes in matter can occur when energy is given off. An exothermic change releases energy. Combustion is a chemical change that releases thermal energy and light.

Chemical Energy The energy stored in the chemical bonds between two atoms is a form of energy called chemical energy.

Chemical Energy: Examples Burning fuels transforms chemical energy and releases some of it as thermal energy. Releases Energy