# Question #67e72

Apr 2, 2014

Ionic compounds do not actually satisfy the octet rule.

The octet rule is that atoms of elements are most stable when the valence shell of ${s}^{2}$ and ${p}^{6}$ are filled with eight electrons, making the atom like a noble gas.

In order to accomplish this atoms release or take on electrons to fill these shells.

For example Calcium ($1 {s}^{2} 2 {s}^{2} 2 {p}^{6} 3 {s}^{2}$) will readily lose the $3 {s}^{2}$ electrons and becomes a $C {a}^{+} 2$ cation.
Fluorine ($1 {s}^{2} 2 {s}^{2} 2 {p}^{5}$) will readily take on an electron to fill $2 {p}^{6}$ and become a ${F}^{-}$ anion.

In becoming ions the atoms fulfill the rule of octet.

Now as ions the $C {a}^{+ 2}$ cation and the ${F}^{-}$ anion, have an electric attraction of opposites to become a $C a {F}_{2}$ ionic compound.