Question

The sum of the oxidation number of all the atoms of a neutral molecule must be:

• A. $0$
• B. $-1$
• C. $+1$
• D. $+2$

Answer 1

The correct option is A $0$

The sum of all oxidation numbers in a neutral compound is zero. The sum of all oxidation numbers in a polyatomic(many-atom) ion is equal to the charge on the ion. This rule often allows chemists to calculate the oxidation number of an atom that may have multiple oxidation states, if the other atoms in the ion have known oxidation numbers.

So answer is $A$.