* Barium (Ba) has two valence electrons. It wants to lose these two electrons to achieve a stable octet (8 electrons) in its outer shell.
* Chlorine (Cl) has seven valence electrons. It wants to gain one electron to achieve a stable octet.
To balance the charges:
* Barium will lose two electrons, becoming a Ba²⁺ ion.
* Two chlorine atoms will each gain one electron, becoming two Cl⁻ ions.
Therefore, you need two chlorine atoms to form an ionic bond with one barium atom. This results in the compound barium chloride (BaCl₂).
