Question

Which statement is true: Mg -> Mg2+ + 2e-

(1) Mg gains 2 electrons (2) Mg2+ loses 2 electrons (3) mg loses 1 electron (4) mg loses 2 electrons

Answer 1

(2) Mg²⁺ loses 2 electrons.

Step-by-step 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.