1. The type of wave that does not require a medium is: a) Standing b) Electromagnetic c) Mechanical

2. In a longitudinal wave, particles of the medium move: a) Perpendicularly to the wave b) 180 degrees out of phase c) Parallel to the wave

3. The period of a wave is: a) The frequency divided by 1 b) The same as the distance between the troughs c) One divided by the frequency

4. The symbol for wavelength is: a) "W" b) Greek letter Lambda c) Greek letter Omega