H2 + 2Na -> 2NaH
NaH + HCI -> NaCl + H2
H2 + S -> H2S
2H2S + 3O2 -> 2SO2 + 2H2O
NaCl = Na⁺ + Cl⁻Ca(NO₂)₂ = Сa²⁺ + 2NO₂⁻Ba(OH)₂ = Ba²⁺ + 2OH⁻Fe₂(SO₄)₃ = 2Fe³⁺ + 3SO₄²⁻