Writing Condensed/Abbreviated Electron Configuration for Chlorine (Cl)

To write condensed electron configurations (also called abbreviated electron configurations) for Chlorine (Cl) we first write the full electron configuration for the element. Once we have the full configuration we put brackets around the config for the Noble Gas core. We can then replace this with the element symbol for the Noble Gas, leaving the rest of the configuration visible (these are the valence electrons).

For example, for Chlorine, atomic number 17 on the Periodic Table:

Chlorine 1s2 2s2 2p6 3s2 3p5 (full)
Chlorine [1s2 2s2 2p6] 3s2 3p5 (Noble Gas in brackets)
Chlorine [Ne] 3s2 3p5 (Condensed config)

For help writing electron configurations for elements:

The condensed electron configuration notation provides an easy way for scientists to write and communicate how electrons are arranged around the nucleus of an atom. It places an emphasis on the valence electrons (the electrons written after the Noble Gas core). This makes it easier to understand and predict how atoms will interact to form chemical bonds.

[d.yix]

never learned this but its pretty easy to do