The number of vibrations (waves) per second.
Particle motion perpidicular to direction of wave motion.
Particles that compress and rarify as energy moves along (parallel to the wave motion).
Distance of one wave crest to crest (or compression to compression).
How fast a wave travels (velocity).
Distance from midpoint to max point of wave.
The electromagnetic spectrum is the range of frequencies of electromagnetic radiation and their respective wavelengths and photon energies.