Figure 40-12 (a) Energy-level diagram
for one electron in a square corral.
(Energy E is in multiples of h2/8mL2.)
A spin-down electron occupies the
lowest level. (b)Two electrons (one
spin down, the other spin up) occupy
the lowest level of the one-electron
energy-level diagram. (c) A third
electron occupies the next energy
level. (d) Four electrons can be put
into the second level. (e) The system’s
ground-state configuration. (f) Three
transitions to consider for the first
excited state. ( g) The system’s lowest
three total energies.