A good way to organize the energy v

A good way to organize the energy values of a given system of electrons is
with an energy-level diagram for the system, just as we did for a single electron in
the traps of Chapter 39. The lowest level, with energy Egr, corresponds to the
ground state of the system.The next higher level, with energy Efe, corresponds to
the first excited state of the system. The next level, with energy Ese, corresponds
to the second excited state of the system, and so on.