The Van der waals forces of attraction operates between

Analysis

The question asks for the specific type of particles between which Van der Waals forces of attraction operate. To answer this, we must understand the nature of intermolecular forces versus intramolecular forces.

Concept Explanation

Van der Waals forces are weak electrostatic attractions that occur between molecules. They are significantly weaker than ionic or covalent bonds (which hold atoms together within a molecule).

• Atoms: Held together by covalent or metallic bonds.
• Cations and Anions: Held together by strong electrostatic forces known as ionic bonds.
• Molecules: These are neutral particles. Because they lack a permanent charge, they rely on weak, temporary fluctuations in electron distribution (London dispersion forces) or permanent dipole-dipole interactions to attract one another. These collective weak attractions are classified as Van der Waals forces.

Step-by-Step Solution

1. Identify the nature of the force: Van der Waals forces are intermolecular forces, meaning they act between molecules, not within them.
2. Evaluate the options: • A (Atoms): Atoms are usually held by covalent bonds (e.g., in diamond) or metallic bonds. • B (Cations) & D (Anions): These are charged ions. The force between them is an ionic bond, which is much stronger than Van der Waals forces. • C (Molecules): Van der Waals forces are specifically defined as the forces of attraction between neutral molecules (such as in noble gases or non-polar covalent compounds like $CO_2$ or $CH_4$).
3. Conclusion: Since Van der Waals forces are responsible for the physical properties (like boiling and melting points) of molecular substances, they operate between molecules.

Correct Answer

The correct option is C.

Exam Tip

Remember the hierarchy of bond strength: Ionic/Covalent (Strong) > Hydrogen Bonding (Moderate) > Van der Waals (Weak). If you see a question asking about forces between "molecules," always look for Van der Waals or Hydrogen bonding as your primary candidates!