The vertical columns on the periodic table are called groups or families<span> because of their similar chemical behavior. All the members of a </span>family<span> of </span>elements<span> have the</span>same<span> number of valence electrons and similar chemical properties</span>
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 would be an Element can't be separated into simpler substances or converted into another substance by chemical process.
Hope that helps!!!
