Question

The covalent and Van der Waals radii of chlorine respectively are:
A. $1.80{A^\circ}$ and $0.99{A^\circ}$
B. $0.99{A^\circ}$ and $1.80{A^\circ}$
C. $0.99{A^\circ}$ and $1.80{A^\circ}$
D. $0.99{A^\circ}$ and $0.99{A^\circ}$

Answer 1

Hint: Interaction between atoms results in different radii based on the bond formation. The interaction may or may not involve the formation of a bond but the activity can occur as a result of interaction.

Complete step by step answer:
The formation of a chloride molecule is based on covalent bond formation between two atoms of chlorine. The covalent interaction is responsible for the formation of the molecular structure which is produced from the interacting atoms.
Covalent radius: If the two atoms of the same species are linked by a single covalent bond then half of the magnitude of separation taking place between the nucleus of the two atoms is known as covalent radius. This separation between the nucleus of the atom is known as internuclear distance and the half of this value defines the covalent radius. Theoretically the separation distance of the nucleus is the covalent bond distance.
Van der Waals radius: The closest two non-bonded atoms of an element can get is defined by a particular distance. Van der Waals radius is considered as half of the distance of that interaction. This closest approach is before bond formation depending on the possibility of interaction.
The covalent radius of chlorine is $1.02{A^\circ}$ and the Van der Waals radius of chlorine is $1.75{A^\circ}$. Among the given options the closest value is seen for the covalent radius to be $0.99{A^\circ}$ for a bonded structure of two chlorine atoms. The closest value for the Van der Waals interaction is seen to be $1.80{A^\circ}$ . Therefore, from the given list of choices as in the question the answer will be: B. $0.99{A^\circ}$ and $1.80{A^\circ}$ .

So, the correct answer is Option B.

Note: The atomic radii of the elements are not similar to that of the covalent and Van der Waals radii because the interaction between atoms of the same element is required to define the radius. Therefore, these two should never be confused as they may seem closely related but the level of interaction differs.