Question

Which of the following substances is associated with the weakest electrostatic forces of attraction?

• A. $HCl$
• B. $NaCl$
• C. $Na$
• D. $C{l}_2$

Answer 1

The correct option is D

$C{l}_2$

Explanation for Correct option: D)$C{l}_2$($Cl-Cl$)

The electronegativity difference between two Cl atoms is zero as they have equal electronegativity, hence they share a pair of electrons equally and form a pure covalent bond. So, the forces of attractions are very weak between Cl atoms.

Explanation for Incorrect options:

A)$HCl$ - H and Cl has an electronegativity difference between $1.4-1.7$ and hence, they share electrons unequally and form a polar covalent bond.

B)$NaCl$- Na and Cl has a large difference in electronegativity and forms oppositely charged ions and are held by strong electrostatic forces of attraction.

C)$Na$- Na forms a metallic bond which forms a crystal with sea of electrons and positive cations and are held by electrostatic forces.

Hence, A) is the correct option - $C{l}_2$ is a pure covalent molecule with weak attractive forces.