1. Определите валентность каждого элемента: HgO, K2S, B2O3, ZnO, MnO2, NiO, Cu2O, SnO2, Ni2O3, SO3, As2O5, Cl2O7, SiH4, CrO3, H2S, CO2, CO, SO3, SO2, Fe2O3, FeO, HCl, HBr, Cl2O5, Cl2O7, PH3, K2O, Al2O3, P2O5, NO2, N2O5, Cr2O3, SiO2, B2O3, SiH4, Mn2O7, MnO, CuO, N2O3, SiH4, CrO3, H2S, CO2, CO, SO3, SO2, Fe2O3, FeO, HCl, HBr, Cl2O5, Cl2O7, PH3, K2O, Al2O3, P2O5, NO2, N2O5, Cr2O3, SiO2, B2O3, SiH4, Mn2O7, MnO, CuO, N2O3.

Определение валентности элементов в соединениях: * HgO: Hg(II), O(II) * K2S: K(I), S(II) * B2O3: B(III), O(II) * ZnO: Zn(II), O(II) * MnO2: Mn(IV), O(II) * NiO: Ni(II), O(II) * Cu2O: Cu(I), O(II) * SnO2: Sn(IV), O(II) * Ni2O3: Ni(III), O(II) * SO3: S(VI), O(II) * As2O5: As(V), O(II) * Cl2O7: Cl(VII), O(II) * SiH4: Si(IV), H(I) * CrO3: Cr(VI), O(II) * H2S: H(I), S(II) * CO2: C(IV), O(II) * CO: C(II), O(II) * SO3: S(VI), O(II) * SO2: S(IV), O(II) * Fe2O3: Fe(III), O(II) * FeO: Fe(II), O(II) * HCl: H(I), Cl(I) * HBr: H(I), Br(I) * Cl2O5: Cl(V), O(II) * Cl2O7: Cl(VII), O(II) * PH3: P(III), H(I) * K2O: K(I), O(II) * Al2O3: Al(III), O(II) * P2O5: P(V), O(II) * NO2: N(IV), O(II) * N2O5: N(V), O(II) * Cr2O3: Cr(III), O(II) * SiO2: Si(IV), O(II) * B2O3: B(III), O(II) * SiH4: Si(IV), H(I) * Mn2O7: Mn(VII), O(II) * MnO: Mn(II), O(II) * CuO: Cu(II), O(II) * N2O3: N(III), O(II)