melting .s of MgBr2 and NaBr

MgBr2 & NaCl are both ionic solid, thus , they both have high melting point
due to the strong forces of attraction between ions. According to Coulombs Law these forces of attraction (lattice energy) increase as the distance between ionic centres decrease & as the charges on the ions increase. The 2 sets of ions carry different charges , however the distance between the ionic centres of Na+ & Cl- is much less than Mg+ & Br- , this means NaCl must absorb more energy to overcome these forces of attraction , hence it has a higher melting temperature .