Question

8. Suppose we used the particle in a three-dimensional cubic box as a crude model for the electron in a hydrogen atom. What value of 1 (the width of the box)

would you have to use so that the energy of transition between the ground state (111) and the first excited energy level (112, 211 or 121) transition for this model would be the same as the exact value determined for the n = 1 → 2 from the Rydberg formula En = 2.1799 x 10-18/n²? Is this a reasonable value for the size of a hydrogen atom?