# When a sodium atom reacts with a chlorine atom to form a compound, the electron configuration of the ions forming the compound are the same as those in which noble gases?

$Z = 11 , \text{sodium}$; the nearest Noble Gas on the Table has $Z = 10$. So when sodium is oxidized it should have an equal number of electrons to .......?
On the other hand, for chlorine, $Z = 17$. Upon reduction, this atom is isoelectronc with the nearest Noble Gas on the Table, for which $Z = 18$.