It would be Violet because it has the shortest wave length, while red has the longest wave length so it comes out the least of the colors.
The speed and wavelength changes as a waves travels to a different depth. Slower and bigger amplitudes in shallower depths. Freq does not change
Lithium 6 would have 6 valence electrons in the outer orbital, while lithium 7 would have 7 in the outer orbital.
