Question

Which energy-level change shown in the diagram below emits electromagnetic radiation with the longest wavelength?

a) an electron moving from 4 to 5
b) an electron moving from 5 to 2
c) an electron moving from 6 to 1
d) an electron moving from 2 to 1

Answer 1

D.

Emission occurs when electrons move from a higher to a lower energy level and the energy of the emitted particle is inversely proportional to the wavelength. Thus, a high wave length means it was a small energy transition.