Answer:
1. wavelength is the distance between two corresponding points on a wave
2. highest = crest, lowest = trough
3. lower
4. higher
5. this could tell you lots of things but given the context of the other questions I would say low energy or if it is asking what kind of wave, then probably radio waves.
6. Electromagnetic spectrum
7. radio waves
8. Ultraviolet
9. Visible light spectrum
10. violet
P.S. this is science (physics) not social studies