NDA General Ability Question (2025) — Solution

Step-by-step solution

The formula of the chloride is XCl_2, which indicates that the valency of element X is 2. Among the given options: Na belongs to Group 1 and has a valency of 1, forming NaCl. Al belongs to Group 13 and has a valency of 3, forming AlCl_3. Mg belongs to Group 2 and has a valency of 2, forming MgCl_2. K belongs to Group 1 and has a valency of 1, forming KCl. Since X forms a chloride with the formula XCl_2 and is a solid with a high melting point (characteristic of ionic chlorides of Group 2 metals), X would most likely be in the same group as Mg. Answer: Mg