An electron is bound in a finite square well of width 1.65 nm and finite depth U0=6E∞, where E∞ is the ground-state energy for an infinitely deep potential well that has the same width.
If the electron is initially in the ground state level of the finite square well, E1=0.625E∞, and absorbs a photon, what maximum wavelength can the photon have and still liberate the electron from the finite well?
Express your answer numerically in meters using three significant figures.