Which statement best describes the difference between intermolecular and intramolecular forces?

• A. Intermolecular forces are always stronger than intramolecular forces.
• B. Intermolecular forces occur between molecules, while intramolecular forces occur within a molecule.
• C. Intramolecular forces are responsible for phase changes, while intermolecular forces hold atoms together in a molecule.
• D. Intermolecular forces only exist in ionic compounds, while intramolecular forces exist in covalent compounds.

Answer: (B)

Verified step by step guidance

1. Step 1: Understand the definitions of intermolecular and intramolecular forces. Intermolecular forces are forces that act between separate molecules, while intramolecular forces are forces that hold atoms together within a single molecule.
2. Step 2: Recognize that intramolecular forces (such as covalent bonds, ionic bonds, and metallic bonds) are generally much stronger than intermolecular forces (such as hydrogen bonding, dipole-dipole interactions, and London dispersion forces).
3. Step 3: Note that intermolecular forces influence physical properties like boiling and melting points because they affect how molecules interact with each other in different phases.
4. Step 4: Understand that intramolecular forces are responsible for the chemical identity of a molecule, holding atoms together to form the molecule itself.
5. Step 5: Evaluate the given statements based on these concepts to identify the correct description: the key difference is that intermolecular forces occur between molecules, while intramolecular forces occur within a molecule.