In any neutral compound, this number must be zero.
The algebraic sum of the oxidation numbers of all atoms in a polyatomic ion is equal to the overall charge of the ion.
the charge on that ion
The oxidation numbers of the elements in a chemical formula, some of which will be positive and others of which will be negative, when multiplied by the numbers of atoms with each oxidation number, must produce products that add to a net result of zero.
For a neutral molecule it is zero, for polyatomic ions the sum is the same as the ionic charge.
The sum of oxidation numbers in a neutral compound is always zero, as the charges balance out. In polyatomic ions, the sum of oxidation numbers equals the charge of the ion. When determining oxidation numbers, rules such as assigning elements in their elemental state an oxidation number of zero and hydrogen an oxidation number of +1 are typically followed.
The algebraic sum of the oxidation numbers of all atoms in a polyatomic ion is equal to the overall charge of the ion.
the charge on that ion
The oxidation numbers of the elements in a chemical formula, some of which will be positive and others of which will be negative, when multiplied by the numbers of atoms with each oxidation number, must produce products that add to a net result of zero.
For a neutral molecule it is zero, for polyatomic ions the sum is the same as the ionic charge.
The sum of oxidation numbers in a neutral compound is always zero, as the charges balance out. In polyatomic ions, the sum of oxidation numbers equals the charge of the ion. When determining oxidation numbers, rules such as assigning elements in their elemental state an oxidation number of zero and hydrogen an oxidation number of +1 are typically followed.
The oxidation number of an atom in its elemental form is 0. In a compound, the sum of oxidation numbers must equal the overall charge of the compound. In a polyatomic ion, the sum of oxidation numbers must equal the charge of the ion. Some elements have fixed oxidation numbers (e.g., alkali metals +1, alkaline earth metals +2).
To establish oxidation numbers, follow these rules: In a compound, the most electronegative element typically has a negative oxidation number (except in compounds with themselves). The sum of all oxidation numbers in a neutral compound is zero, and in a polyatomic ion, it equals the charge of the ion. Fluorine always has an oxidation number of -1 in compounds. Hydrogen usually has an oxidation number of +1, and oxygen is usually -2.
In a neutral compound, the sum of oxidation numbers of all atoms will be zero. In a polyatomic ion, the sum of oxidation numbers of all atoms will be equal to the charge of the ion. The oxidation number of an element in its elemental form is zero. Fluorine always has an oxidation number of -1 in compounds. Oxygen usually has an oxidation number of -2 in compounds.
The sum of the oxidation numbers in the phosphate ion (PO4^3-) is -3. Each oxygen atom has an oxidation number of -2, totaling -8. The oxidation number for phosphorus is +5 to offset the oxygen atoms and give a total charge of -3 for the ion.
To find the oxidation number or charge of a polyatomic ion, consider the known charges of the individual atoms within the ion. For example, in the sulfate ion (SO4)2-, oxygen typically has an oxidation number of -2, and sulfur would then have an oxidation number to balance the charge of the ion. The sum of the oxidation numbers of all the atoms in the ion should equal the overall charge of the ion.
In principle, only by comparing the chemical formula for the compound with the formulas of ions known to be polyatomic to determine whether the sequence of letters and subscript numbers (if any) in any part of the chemical formula corresponds to the sequence of letters and subscript numbers in the formula of a know polyatomic ion.
Formulas for compounds do not include oxidation numbers because these numbers are specific to an individual atom within a compound, and the compound as a whole remains neutral. Including oxidation numbers in the formula would imply a charge on the compound, which is not accurate for neutral compounds. The formula provides the ratio of atoms in the compound, while oxidation numbers are used to determine how electrons are distributed in a chemical species.