He+ ion consists of a nucleus which is an alpha particle plus one orbiting electron.Hence it has a net positive charge.
a)Derive an expression for the electron state energies
b)what is the wavelength associated with a transition between the lowest two energy states?
The Attempt at a Solution
For part a) i figured it out to be E=(-4R)/(n^2) where R is the rydbergs constant
for part b) im having trouble not sure where to begin