crests and troughs
 the high and low points of a wave, respectively

speed
 how fast a wave moves in a given direction
the speed of light in a vacuum (c) is 3 x 10^{8} m/s

wavelength ()
 the distance between two consecutive crests or troughs
review the appropriate metric prefixes

frequency (v)
 the number of waves that pass a given point in a given time period
the unit for frequency is hertz (sec^{1})
for light waves c = v *

amplitude
 the "height" of a wave

energy (E)
 the energy of one photon of light
E = h * v (where h is Planck's constant = 6.626 x 10^{34} J^{.}s)
