Question

the chemical formula of X is XCl2, then why X belongs to 2nd group but not 16th group ?​

Answer 1

Answer:

Because its combining capacity is or valence is 2.

Explanation:

As Cl has a valency of 1 ,while forming compounds X will form Cl2 as it has valency 2.

The metals with valency 2 belongs to the 2nd group.

Answer 2

Mg has the valency 2. So, when it combine with chlorine having valency 1, it forms Mgcl2. Whereas Na has valency 1, Al has valency 3 and Si has valency 4.