physics crossword #2

5. a wave's peak to peak or trough to trough
6. another way of saying wave cycle
8. a single quantum of electromagnetic energy
9. Waves that need a medium in which to propagate.
12. Waves that can propagate in a vacuum, how energy gets here from the sun, can also propagate in a medium
13. when photons of light are all aligned in the same direction

1. light spectrum that can be seen by human eyes from red to violet
2. reciprocal of time period
3. measurements sound dB
4. electromagnetic radiation with frequency too low to be seen by human eyes
7. Unit used to measure the period of a wave.
8. Amount of time required for a wave to complete one cycle.
10. A disturbance in space and time that carries energy from one place to another.
11. the light which has the lowest frequency in the visible spectrum