electron1
Favorite Answer
The charge of a nitrate ion is -1. To balance two nitrate ions, the oxidation number of copper must be +2.
pisgahchemist
Oxidation state ....
The oxidation state of copper metal is zero. Any element in the elemental state has an oxidation state of zero. Cu, H2, P4, S8 .... all of these are in the elemental state, and all have oxidation states of zero.
When an ion is the free state, as in a gas or in aqueous solution, then it's oxidation state is equal to the charge on the ion. Cu2+(aq) ions have an oxidation state of +2.