Define valence of an element. Find the valency of chlorine and magnesium

Explanation:

The number of electrons that an atom of an element loses, gains, or shares during a chemical reaction in order to complete its octet is known as its valency.

The number of valence electrons in chlorine (2,8,7) is 7, but the atom will not lose these 7 electrons. The atom will gain one electron to complete its octet at this point. As a result, the valency will be 1.

Magnesium (2, 8, 2) has two valence electrons. To fill its outermost orbit, the atom will lose two electrons. As a result, the valency is 2.

Final Answer:

Valency of chlorine = 1

Valency of magnesium = 2