The perodic table of elements is based on the fact that atoms with the same number of electrons
outside a closed shell have similar properties. The rows of the periodic table contain the following
states.
- 1s
- 2s, 2p
- 3s, 3p
- 4s, 3d, 4p
- 5s, 4d, 5p
Soon after, the periodicity is broken and special “series” are inserted to contain the 4f and 5f shells.
26.5 The Nuclear Shell Model
We see that the atomic shell model works even though the hydrogen states are not very good
approximations due to the coulomb repulsion between electrons. Itworks because of thetight
binding and simplicity of closed shells. This isbased on angular momentum and the
Pauli principle.