Определить валентность HgO,K2S,B2O3,ZnO,MnO2,NiO,Cu2O,SnO2,SO3,As2O5,Cl2O7

Hg(II)O(II),K2(I)S(II),B2(III)O3(II),Zn(II)O(II),Mn(IV)O2(II),Ni(II)O(II),Cu2(I)O(II),Sn(IV)O2(II),S(VI)O3(II),As2(V)O5(II),Cl2(VII)O7(II)