Which of the following molecules would have the strongest intramolecular forces?

• A. CH4 (methane)
• B. NaCl (sodium chloride)
• C. CO2 (carbon dioxide)
• D. O2 (oxygen gas)

Answer: (B)

Verified step by step guidance

1. Identify the types of intramolecular forces present in each molecule or compound. Intramolecular forces are the forces that hold atoms together within a molecule or compound, such as covalent bonds or ionic bonds.
2. For CH4 (methane), recognize that it is a covalent molecule with nonpolar covalent bonds between carbon and hydrogen atoms.
3. For CO2 (carbon dioxide), note that it is a linear molecule with polar covalent bonds, but the molecule is overall nonpolar due to its symmetry.
4. For O2 (oxygen gas), understand that it is a diatomic molecule with a nonpolar covalent bond between the two oxygen atoms.
5. For NaCl (sodium chloride), identify that it is an ionic compound composed of positively charged sodium ions (Na⁺) and negatively charged chloride ions (Cl⁻), which are held together by strong ionic bonds, a type of intramolecular force stronger than covalent bonds in these molecules.