Ответ:

Используем: Mg = 24, Al = 27, P = 31, S = 32, Cl = 35,5, C = 12, O = 16, N = 14, H = 1.

Задание 1. Ar(Mg) = 24; Ar(Al) = 27; Ar(P) = 31; Ar(S) = 32; Ar(Cl) = 35,5.

Задание 2.

Mr(CO₂) = 12 + 2 · 16 = 44.

Mr(SO₂) = 32 + 2 · 16 = 64.

Mr(NH₃) = 14 + 3 · 1 = 17.

Mr(CH₄) = 12 + 4 · 1 = 16.

Mr(HCl) = 1 + 35,5 = 36,5.