In a reduction half-reaction, which amount is shown? a. the number of atoms needed to balance the equation b. the number of electrons and element gains c. the number of electrons an element loses d. the number of electrons needed to balance the equation

            In a reduction half-reaction the number of electrons an element gains are shown.

Explanation:
                   Reduction reactions are those reactions in which an atom gains electron (s). In a cell a redox reaction is carried out either utilize electricity or produce electricity. Let suppose a general redox reaction shown below,

                                  A⁺  +  B      →      A  +  B⁺

For above reaction the reduction half-reaction is as follow,

                                 A⁺  +  1 e⁻     →      A

(Hence, in this reaction only the number of electrons an element gain are shown)

And the oxidation half reaction is as follow,

                                B      →       B⁺  +  1 e⁻