umm...anyone wanna help me with this?

[ManBearPig]

An electron moves between 2 energy levels and a photon of light is emitted. The energy of this photon is 3.90 x 10-19 joules. What is the wavelength of this photon in meters?


i dont want the answer necessarily, just how to do it. i know it involves E=Hv

 

[minendo]

Been quite some time, but I think you just do the following:

E=Hv

wavelength * v = c