Question

Determine the energy in ev of a photon when electron transit from third level to the first level

energy of hydrogen atom *

A) 12 ev
B) O 1.2 ev
C) 0.12 ev

Answer 1

One way of writing frequency difference for "Lyman" series is

f = 3.289 * 10^15 (1 / 1^2 - 1 / n^2)

f = 3.289E15 * (1 - 1/9) = 2.924E15 as frequency difference of terms

E = h f = 6.63E-34 * 2.924E15 = 1.938E-18 Joules

1 eV = 1.60 * 10^-19 Joules

1.938 / .16 = 12.1 eV