Fundamentals of Electrochemistry

Professor Dr. Loutfy H . Madkour

element is 0 2) Total of the O.S.'s of atoms in a molecule or ion is equal to the total charge on the molecule or ion. 3) Group 1A and Group 2A metals have O.S. of +1 and +2 respectively. 4) F always has an O.S. of -1. Cl also has O.S. of -1 unless it is bonded to oxygen or fluorine. 5) H almost always has an O.S. of +1. 6) O has O.S. of -2 (unless bonded to itself or F) 7) When bound to metals, group 7A, 6A and 5A elements have O.S.'s of -1, -2, -3 respectively.