A Proton Is in a One-Dimensional Box of Length 2 $\times$

Multiple Choice

A proton is in a one-dimensional box of length 2 $\times$ 10^-15 m.Find the wavelength of the photon emitted for a transition between the first excited state and the ground-state.

A) 8.1 $\times$ 10^-6 nm
B) 6.1 $\times$ 10^-6 nm
C) 24 $\times$ 10^-6 nm
D) 16 $\times$ 10^-6 nm
E) 12 $\times$ 10^-6 nm