pretts4tennyaev pretts4tennyaev 02-09-2016 Chemistry contestada the percent composition by mass of magnesium MgBr2 (gram formula mass= 184 grams/mole) is equal to... a- 24/184 x 100 b- 160/184 x 100 c- 184/24 x 100 d- 184/160 x 100