Question

An electron absorbs a photon of wavelength 2.6*10^(-5)m. If the electron has a ground (original) state (level) of n=3, to which level is the electron promoted?

Answer 1

From Rydburg's Equation , 1/ λ = R[(1/n_i²) – (1/n_f²)]
   Where R = Rydburg's constant = 10.96 x10⁶ m^-1
               λ = wavelength = 2.6X10^-5 m
               n_i = 3
               n_f = ?
Plug the values we get [(1/n_i²) – (1/n_f²)] = 1 / (Rλ )

= 3.51x10^-3

  [(1/3²) – (1/n_f²)] = 3.51x10^-3

  (1/n_f²) = 0.1076

n_f² = 9.3

n_f = 3.05   

So this wavelength is not enough to promote the electron to higher energy level