For example, the electronic configuration of phosphorus (P) is 1s 2s 2p 3s 3p so that there are 5 valence electrons (3s 3p), corresponding to a maximum valence for P of 5 as in the molecule PF; this configuration is normally abbreviated to [Ne] 3s 3p, where [Ne] signifies the core electrons whose configuration is identical to that of the noble gas neon.