Magnesium bromide ( criss cross method)
Answers
Magnesium has an electronic configuration of 2.8.2. It has to lose 2 electrons to attain a stable electronic configuration and octet valance shell structure resembling that of noble gases. Hence it has a charge of 2+, Mg2+.
Bromine is a diatomic halogen molecule that exists as Br2, volatile liquid at room temperature and pressure. As an ion it has a charge of 1-, Br-because it has to gain an electron to attain stable electronic configuration and octet valance shell structure resembling that of noble gases.
So now we have got Mg2+ and Br-. To balance the chemical formula, there should be 2 bromide ions and one magnesium ion.
2*(-1)+ (+2) = 0, the compound has an overall oxidation state of 0, it is neutrally charged.
Hence the chemical formula is MgBr2.