A wave is a propagating disturbance that travels through matter (mechanical wave) or space (electromagnetic wave) transferring only energy.
A wave’s energy is proportional to its frequency. If a wave’s frequency doubles, its energy also doubles.
A wave’s energy is proportional to the square of its amplitude. If a wave’s amplitude doubles, its energy quadruples ().
Transmission is when a wave passes from a medium into another. Refraction is the change in direction of a wave passing from one medium to another with a different density.
Absorption is when a wave loses energy as it transmits into a material. Reflection is the change in direction of a wave at a boundary or fixed end.