а) Mᵣ(MgSO₃) = Aᵣ(Mg) + Aᵣ(S) + 3Aᵣ(O) = 24 + 32 + 3*16 = 24 + 32 + 48 = 104 а.е.м.
б) Mᵣ(Ba(NO₃)₂) = Aᵣ(Ba) + 2Aᵣ(N) + 3*2Aᵣ(O) = 137 + 2*14 + 6*16 = 137 + 28 + 96 = 261 а.е.м.
в) Mᵣ(Al(OH)₃) = Aᵣ(Al) + 3Aᵣ(O) + 3Aᵣ(H) = 27 + 3*16 + 3*1 = 27 + 48 + 3 = 78 а.е.м.
