Answer:
Energy of 1eV is absorbed to move from n=2 to n=3
Explanation:
Since;
E =hc/λ
h= Planks's constant = 6.6 * 10^-34 Js
c= speed of light = 3 * 10^8 ms-1
λ = wavelength = 1240 * 10^-9 m
E =6.6 * 10^-34 * 3 * 10^8/1240 * 10^-9
E = 1.6 * 10^-19 J or 1eV
From the diagram, It is clear that an energy of 1eV is absorbed to move from n=2 to n=3