Energy exists in many forms, including light, heat, sound, and mechanical energy.

Light Energy

Light travels through air and space as waves of energy.

The initial energy for all light sources comes from the sun.

Light rays can reflect or bounce off a surface or an object in much the same way that a thrown rubber ball bounces off a wall.

Heat Energy

Heat is the amount of energy contained in a substance or material. 

Temperature and heat are not the same thing. Temperature is the measurement of how hot or cold something is.

Adding heat energy often causes changes in matter, such as melting a snowman.

Taking away heat energy can also lead to changes in matter, such as a freezer keeping ice cream cold.