The atomic number for sodium is 11. We can therefore say that sodium contains eleven protons. We can also infer that sodium has eleven electrons because, in neutral molecules, the number protons is equal to how many electrons.
The electron configuration can be written in two ways: in the complete electron configuration, which shows all electrons, or in the condensed electron configuration, which only shows the noble gas and valence electrons.
Na- 1s2 3s2 2p6 3s1 (complete configuration)
OR
Na – [Ne]3s1 (condensed version)
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