The figure shows part of the energy level diagram of a certain atom. The energy spacing between levels 1 and 2 is twice that between 2 and 3 . If an electron makes a transition from level 3 to level 2 , the radiation of wavelength $\lambda$ is emitted. What possible radiation wavelengths might be produced by other transitions between the three energy levels?
A) only $\lambda / 2$
B) both $\lambda / 2$ and $\lambda / 3$
C) only $2 \lambda$
D) both $2 \lambda$ and $3 \lambda$

Question

Quizplus · Accepted Answer

Given that the energy spacing between levels 1 and 2 is twice that between 2 and 3, the transition from 3 to 2 emits radiation of wavelength $\lambda$. The transition from 2 to 1 would emit radiation of twice the energy (since the energy difference is twice as much), which corresponds to half the wavelength ($\lambda/2$). The transition from 3 to 1 involves the sum of the energy differences of the 3 to 2 and 2 to 1 transitions, resulting in a wavelength of $\lambda/3$.

The Figure Shows Part of the Energy Level Diagram of a Certain