Answer
Reduction
Procedure
A redox reaction is a reaction that involves the transfer of electrons between chemical species. During a redox reaction, some species undergo oxidation, or the loss of electrons, while others undergo reduction or the gain of electrons.
An atom’s oxidation number is the charge that the atom would have if all of the bonds to the atom were completely ionic. An increase in oxidation number during a reaction corresponds to oxidation, while a decrease corresponds to reduction.