Why do 8 electrons form a stable shell? [ENDORSED]

[Ace 3F]

I'm pretty sure that others have probably gone over this before but I don't recall having learned why exactly it is 8 electrons that form a stable shell, I know it has to do with electron spins although I'm not sure what dictates it exactly.

Thank you!

[Alexandra_Shambayate_2L]

Noble gases have eight electrons and they are considered the most stable elements, therefore it is most ideal and stable for other elements to have a shell of eight electrons to be at its most stable point.

[Chem_Mod]

In the p-block it is the result of filled s and p subshells = 8e-
s, p_x, p_y, p_z

Most of the covalent bonds in molecules involve p-block elements, hence our octet guideline for most molecules, especially biological compounds involving C, O, N, Cl.

In the d-block it is 18e- due to the s, p, and 5 d-states.

Ask me after class if this is not clear.