Mg(clo2)2 and al(clo2)3 contain the same number of atoms
how many atoms of each kind are in these formulas?

Mg(ClO2)2 has an atom of magnesium, 2 moles of chlorine and 4 moles of oxygen. Al(ClO2)3, on the other hand, is composed of one mole of aluminum, one mole of chlorine and six moles of oxygen. The number of molecules of both is equal to 6.022 x10^23 molecules per mole of the compound.