Question

The element $X$ forms a chloride with the formula $X{Cl}_3$, which is solid with a high melting point. $X$ would most likely be in the same group of the Periodic table as:

• A. $Na$
• B. $Mg$
• C. $Al$
• D. $Si$

Answer 1

Answer: (C)

$Al$

An element 'X' forms a chloride with formula XCl${}_3$

In the compound, both elements are shared electrons to form the chemical bonds.

Sharing of elements depends upon their combining capacity known as valency of the element.

Since we know that the valency of lithium, sodium magnesium aluminium and calcium is 1,1,2,3 and 2 respectively.

In this, there is three chlorine and we know that each chlorine required one electron to complete its shell.

So, the required element is Aluminium.

Hence, the correct option is $\text{C}$