When an electron in a box makes a transition from the $=1$ energy level to the $=2$ level, it

absorbs a photon of wavelength $426$ nm$.$ What is the wavelength of that photon when the

electron undergoes a transition

a$)$ from the $=2$ to the $=3$ energy level? Answer: $255\mathrm{.}7$ nm

b$)$ from the $=1$ to the $=3$ energy level? Answer: $159\mathrm{.}8$ nm

c$)$ What is the width $$ of the box? Answer: $0\mathrm{.}62$ nm