When a substance is oxidized, it
Loses electrons
Gains oxygen atoms
Gains electrons
Loses protons (H+ ions)
Correct answer is A
When a substance is oxidized, it loses electrons. Oxidation is a chemical reaction that involves the moving of electrons. Specifically, it's a process that involves the substance losing electrons. This is an old definition of oxidation, based on the oxygen's role in reactions. The modern definition of oxidation involves an increase in oxidation state by a molecule, atom, or ion.