Waves in the electromagnetic spectrum
Waves in the electromagnetic spectrum vary in wavelength from very long radio waves to very short gamma-rays.
Radio waves vary in length from very long waves (up to a kilometer) to shorter waves the size of buildings and people.
Microwaves are around the size of an insect.
Infrared waves are about the length of a pinhead.
Visible waves are the size of bacteria.
Ultraviolet waves are about the length of molecules.
X-rays are about the length of atoms.
Gamma-rays are the smallest waves, smaller than the size of the nucleus of an atom.