1) The charge of copper on the reactant side is 0 (it is solid copper thus not charged).
2) The charge of the copper ions on the product side is 2+ (when ionized it is evident that Copper in Copper Nitrate is in its 2+ form)
3) Copper was Oxidized since its oxidation state increased from 0 as a reactant to +2 as a product
4) The number of electrons transferred is 2 electrons. Since oxidation is the loss of electrons, then Copper lost 2 electrons.
