Final answer:
The energy levels for the states n of an electron confined between two impenetrable walls can be determined using the equation E = -13.6 eV/n², where E is the energy level and n is the principal quantum number.
Step-by-step explanation:
The energy levels for the states n of an electron confined between two impenetrable walls can be determined using the equation E = -13.6 eV/n², where E is the energy level and n is the principal quantum number. In this case, since the distance between the walls is 0.20 nm, we can calculate the energy levels by considering the values of n for which the wavelength of the electron is an integral multiple of twice the distance between the walls.
The wavelength of the electron is given by the de Broglie wavelength equation λ = h / √(2mE), where λ is the wavelength, h is the Planck constant, m is the mass of the electron, and E is the energy level. By substituting the values and rearranging the equation, we can find the energy levels for different values of n.
For example, when n = 1, the energy level is -13.6 eV, when n = 2, the energy level is -3.4 eV, and so on. The energy levels become less negative as n increases, indicating that the electron has more energy and is further away from the walls.