| A | B |
|---|---|
| He . Ne . Ar . Kr . Xe = ns2np6 | Gas rares |
| F . CL . Br . i = ns2np5 | Halogénes |
| O . S . Se . Te = ns2np4 | Oxygéne |
| N . P . As . Sb = ns2np3 | Azote |
| C . Si . Ge . Sn = ns2np2 | Carbone |
| B . Al . Ga . In = ns2np1 | Bore |
| Be . Mg . Ca . Sr = ns2 | Alcalino terreux |
| H . Li . Na . K . Rb = ns1 | Alcalins |