Question

The energy required to remove an electron from an atom

Answer 1

Answer:

The electron energy levels for a helium atom demonstrate a number of features of multi-electron atoms.

One electron is presumed to be in the ground state, the 1s state. An electron in an upper state can have spin antiparallel to the ground state electron (S=0, singlet state, parahelium) or parallel to the ground state electron (S=1, triplet state, orthohelium).