Назовите валентность соединений: а)cl2o7, cl2o, clo2; б)fecl3, fecl2; в)mns, mno2, mnf4, mno, mncl4; г)cu2o, mg2si, sicl4, na3n, fes.

Cl2(VII)O7(II), CL2(I)O(II), CI(IV)O2(II)
Fe(III)Cl3(I), Fe(II)Cl2(I)
Mn(II)S(II), Mn(IV)O2(II), Mn(IV)F(I), Mn(II)O(II), Mn(IV)Cl4(I)
Cu2(I)O(II), Mg2(IV)Si(II), Si(IV)CI4(I), Na3(I)N(III), Fe(II)S(II).