Which of the following elements shows variable valency ?
(1) Na
(2) Mg
(3) Fe
(4) Zn
Correct option: (3) Fe
Explanation:
Elements of d - block show more than one valency.
Iron (Fe) show variable valency because it is a d- block element.
Iron shows 2 & 3 valency i.e. Fe+2(ferrous) and Fe+3 (ferric)
