Ответ:

Mr[Al2O3] = Ar[Al] * 2 + Ar[O] * 3 = 26.9815386 * 2 + 15.9994 * 3 = 101.9612772 = 102

Mr[CO2] = Ar[C] + Ar[O] * 2 = 12.0107 + 15.9994 * 2 = 44.0095 = 44

Mr[Fe2O3] = Ar[Fe] * 2 + Ar[O] * 3 = 55.845 * 2 + 15.9994 * 3 = 159.6882 = 160

Mr[BaO] = Ar[Ba] + Ar[O] = 137.327 + 15.9994 = 153.3264 = 153

Объяснение: