Answer: What are the numbers of valence electrons for each atom?
Explanation:
For formation of a neutral ionic compound, the charges on cation and anion must be balanced. The cation is formed by loss of electrons by metals and anions are formed by gain of electrons by non metals.
The cations and anions combine and their oxidation states are exchanged and written in simplest whole number ratios to give neutral ionic compound.
The oxidation states are known by their ability to gain or lose electrons which is decided by the number of valence electrons.
