Na₂O is an ionic compound. Na is in group 1 which means it has one electron in the outer shell. O is in group 6 so it has 6 electrons in the outer shell.
To become stable atoms need to either lose the electrons in the outer shell or gain electrons to gain a complete outer shell configuration.
To become stable Na loses its outer electron and becomes positively charged. It only loses one electron, so net charge is +1. O to become stable gains 2 electrons to complete its outer shell and becomes negatively charged. since it gains 2 electrons, the net charge is -2.
cation - Na⁺
anion - O²⁻
O gains 2 electrons but Na can give only one electron, therefore 2 Na⁺ ions are required.
the compound can be written by exchanging the charges
ions Na⁺ O²⁻
charge +1 -2
exchange Na₂O
Correct answer is Na has +1 charge and O has -2 charge
