Differentiate between cations and anions.
Cations: Positively charged ions are called Cation.
Anions: Negatively charged one calls Anions.
An ionic compound contains anions and cations such number that the compound is electrically neutral Metal atoms generally lose one or more electrons and form cations.
For example, Na forms Na+ by losing one electron, Ca forms Ca+2 by losing two electrons The Non-metal atoms usually a one or more electrons and form anions.
For example, chlorine atom gains one electron and forms Cl- ion O- atom gain two electrons and forms O2 ions.