Answer:
(2) Mg²⁺ loses 2 electrons.
Explanation:
Let's consider the following half-reaction.
Mg ⇒ Mg²⁺ + 2 e⁻
Magnesium is a metal that loses 2 electrons to fulfill the octet rule. When magnesium loses electrons, the oxidation number increases from 0 to +2. This kind of half-reaction is known as oxidation, and has to be accompanied by a reduction of another species.
