CO2 - C(IV), O(II);

P2O5 - P(V), O(II);

Al2O3 - Al(III), O(II);

MgO - Mg(II), O(II);

Mn2O7 - Mn(VII), O(II);

HCl - H(I), Cl(I);

SO2 - S(IV), O(II);

SO - S(II), O(II);

NH3 - N(III), H(I);

N2O5 - N(V), O(II);

CuO - Cu(II), O(II);

Cu2O - Cu(I), O(II);

NO - N(II), O(II).