How is relative formula mass calculated?
Relative atomic mass, is the number at the top of an element in the periodic table, for example magnesium’s relative atomic mass is 35.5. So if you had MgCl2, the relative formula mass is all the relative atomic masses of the elements in the compound added together. MgCl2 would be 24 (for magnesium) plus 35.5 x 2 (for the 2 atoms of chlorine) so the relative formula mass is 95. Hope this helps!
