Energy, I think, haven't done that since 8th grade
It’s oxidation number is +6
Hertz is units for frequency. (waves per second)
wavelength = speed/frequency
if you're given the speed use that to calculate, if not then you can probably assume it's a wave of light and use the speed of light (3x10^8 m/s) to calculate.
wavelength = (3x10^8)/(1.28x10^17)
= 0.000000002 m
= 2.34 nm
your answer is <u>D</u><u>.</u><u> </u>physical change, because a new substance is not formed.