Electron arrangement of chlorine

Answer 1

Chlorines electron configuration can be described in a few different ways - it also depends on whether you are talking about chlorine gas or chlorine the atom.

For the atom - chlorine has 17 electrons. Simply describes the electron arrange could be called 2, 8, 7 (where the number represents the # of electrons in each shell.

From the more advanced atomic orbital theory - chlorines electron configuration could be notated as such: 1s2 2s2 2p6 3s2 3p5 (where the last number in each is superscript).

For chlorine gas, the electron configuration is described using molecular orbital theory (university level) as such:

non-valence electrons are ignored - since they are too far separated to combine their wavefunctions meaningfully - so we only consider valence electrons (3rd shell ie 3s and 3p in this case)

σ3s2 σ3s*2 σ3p2 π3p4 π3p*4

Answer 2

2,8,7

or more specifically

1s2 2s2 2p6 3s2 3p5