HClO3: H = +1, Cl = +5, O = -2CuCO3: Cu = +2, C = +4, O = -2K2CrO4: K = +1, Cr = +6, O = -2Fe(OH)2: Fe = +2, O = -2, H = +1KMnO4: K = +1, Mn = +7, O = -2
HClO3: H = +1, Cl = +5, O = -2
CuCO3: Cu = +2, C = +4, O = -2
K2CrO4: K = +1, Cr = +6, O = -2
Fe(OH)2: Fe = +2, O = -2, H = +1
KMnO4: K = +1, Mn = +7, O = -2