4.736 x 10^-19 / 1.602 x 10^-19 J
= 2.96 eV
WOW! Thank you.
Okay, since my value is between energy levels f and e, I would say No, Mercury could not emit a wavelength of 420nm, because Photons are only emitted going down energy levels, and must be a certain value as shown in the calculations above.