The electromagnetic spectrum covers all possible wavelengths and frequencies of radiation. From lowest frequency (longest wavelength) to highest frequency (shortest wavelength) radiation: radio waves → microwaves → infrared waves → visible light → ultraviolet light → X-rays → gamma rays.

An element is matter than cannot be separated into different types of matter by ordinary chemical methods.

Momentum is a measure of how difficult it is for a moving object to stop and is calculated by multiplying the object's mass by its velocity: \(\vec{p} = m\vec{v}\). Like velocity, momentum is a vector quantity as it expresses force applied in a specific direction.

Power is the rate at which work is performed or work per unit time: \(P = {w \over t}\) and is measured in watts (W).

A proton is a subatomic particle found in the nucleus of an atom. It carries a positive electric charge.