Consider the following statements about atomic radii: 1. Covalent radius is defined as the total distance between the nuclei of two bonded atoms. 2. van der Waals radius is half the distance between two identical atoms in separate molecules in a solid. 3. The van der Waals radius is generally larger than the covalent radius. Which of the statements given above is/are correct?

The correct option is 2 and 3 only . Explanation Atomic radius is not a fixed quantity because the electron cloud surrounding an atom does not have a sharp boundary. Consequently, atomic size is expressed in terms of operational definitions such as covalent radius, van der Waals radius, or metallic radius, depending on the bonding state of the atoms. Statement-wise Analysis: - Statement 1 is Incorrect. The covalent radius is defined as one-half of the distance between the nuclei of two identical atoms bonded by a single covalent bond. The statement incorrectly defines it as the "total distance," which refers to the bond length (internuclear distance), not the radius. - Statement 2 is Correct. The van der Waals radius represents the overall size of the atom, including its valence shell in a non-bonded context. It is defined as one-half of the internuclear distance between two identical atoms belonging to two adjacent molecules of an element in the solid state. - Statement 3 is Correct. The formation of a covalent bond involves the overlap of atomic orbitals, which pulls the nuclei closer together. In contrast, van der Waals forces are weak attractive forces between non-bonded atoms where no orbital overlap occurs. Consequently, the van der Waals radius is always larger than the covalent radius for the same element. Key Takeaway: Covalent radius involves orbital overlap (shorter distance), whereas van der Waals radius represents the non-bonded distance of closest approach (longer distance). Therefore, $r_{vdw} > r_{metallic} > r_{covalent}$.

NCERT Class 11 Science — Chapter 2: Chemical Bonding and Molecular Structure

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Consider the following statements about atomic radii:

Covalent radius is defined as the total distance between the nuclei of two bonded atoms.
van der Waals radius is half the distance between two identical atoms in separate molecules in a solid.
The van der Waals radius is generally larger than the covalent radius.

Which of the statements given above is/are correct?

Official previous-year question

Verified 1 Aug 2026.

Options

A1 and 2 only
B2 only
C2 and 3 only
D1, 2 and 3

Did you get this right?

Solution

The correct option is

2 and 3 only

Explanation

Atomic radius is not a fixed quantity because the electron cloud surrounding an atom does not have a sharp boundary. Consequently, atomic size is expressed in terms of operational definitions such as covalent radius, van der Waals radius, or metallic radius, depending on the bonding state of the atoms.

Statement-wise Analysis:

Statement 1 is Incorrect.
The covalent radius is defined as one-half of the distance between the nuclei of two identical atoms bonded by a single covalent bond. The statement incorrectly defines it as the "total distance," which refers to the bond length (internuclear distance), not the radius.
Statement 2 is Correct.
The van der Waals radius represents the overall size of the atom, including its valence shell in a non-bonded context. It is defined as one-half of the internuclear distance between two identical atoms belonging to two adjacent molecules of an element in the solid state.
Statement 3 is Correct.
The formation of a covalent bond involves the overlap of atomic orbitals, which pulls the nuclei closer together. In contrast, van der Waals forces are weak attractive forces between non-bonded atoms where no orbital overlap occurs. Consequently, the van der Waals radius is always larger than the covalent radius for the same element.

Key Takeaway:
Covalent radius involves orbital overlap (shorter distance), whereas van der Waals radius represents the non-bonded distance of closest approach (longer distance). Therefore, $r_{vdw} > r_{metallic} > r_{covalent}$.

Your note

More from Chapter 2: Chemical Bonding and Molecular Structure

Which type of bond is formed by the electrostatic attraction between positive and negative ions?

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In a Lewis symbol, what do the dots surrounding the element symbol represent?

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For main group elements, the group valence is generally equal to:

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Who introduced the term ‘covalent’ to describe the sharing of electrons between atoms?

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Which of the following molecules is paramagnetic according to Molecular Orbital Theory?

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Keep practising Chapter 2: Chemical Bonding and Molecular Structure

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Solution

The correct option is

2 and 3 only

Explanation

Statement-wise Analysis:

Statement 1 is Incorrect.
The covalent radius is defined as one-half of the distance between the nuclei of two identical atoms bonded by a single covalent bond. The statement incorrectly defines it as the "total distance," which refers to the bond length (internuclear distance), not the radius.
Statement 2 is Correct.
The van der Waals radius represents the overall size of the atom, including its valence shell in a non-bonded context. It is defined as one-half of the internuclear distance between two identical atoms belonging to two adjacent molecules of an element in the solid state.
Statement 3 is Correct.
The formation of a covalent bond involves the overlap of atomic orbitals, which pulls the nuclei closer together. In contrast, van der Waals forces are weak attractive forces between non-bonded atoms where no orbital overlap occurs. Consequently, the van der Waals radius is always larger than the covalent radius for the same element.