Metallic and non-metallic elements can both be extracted by electrolysis. Which of the following will undergo reduction at the electrode?

Hydrogen

Reason — Reduction (gain of electrons) takes place at the cathode. Hydrogen ions (H⁺) migrate to the cathode and gain electrons to be reduced to hydrogen gas. Bromine, chlorine and oxygen are formed by oxidation (loss of electrons) at the anode.

2H⁺ + 2e^- ⟶ H₂