Step 1: Understanding the Concept:
Intermolecular forces (IMFs) are the forces of attraction between neighboring molecules. These forces are much weaker than intramolecular forces (covalent/ionic bonds) but determine physical properties like boiling point and state of matter.
- Dipole-dipole forces occur between polar molecules.
- Hydrogen bonding occurs when H is bonded to highly electronegative elements like N, O, or F.
- London dispersion forces (or Van der Waals forces) exist between all molecules and are the only forces present in non-polar molecules. They arise from instantaneous, temporary dipoles created by electron motion.
Step 2: Key Formula or Approach:
To identify the force, we must determine the polarity of dinitrogen (\( N_2 \)).
A molecule is non-polar if there is no net dipole moment. In homonuclear diatomic molecules, the electronegativity difference between atoms is zero.
Step 3: Detailed Explanation:
Dinitrogen is a homonuclear diatomic molecule represented by the formula \( N \equiv N \).
Since both nitrogen atoms are identical, they share the bonding electrons equally. There is no permanent separation of partial charges (\( \delta+ \) or \( \delta- \)).
As a result, \( N_2 \) has zero dipole moment and is non-polar.
- Because it is non-polar, it cannot have dipole-dipole interactions.
- It does not contain a Hydrogen atom bonded to a highly electronegative atom, so hydrogen bonding is ruled out.
- Dipole-induced dipole interactions require at least one polar species to be present.
The only force remaining is the London dispersion force, which is a universal force caused by temporary electronic fluctuations. These weak forces allow \( N_2 \) to be liquefied only at extremely low temperatures.
Step 4: Final Answer:
Since \( N_2 \) molecules are non-polar, the only intermolecular force acting between them is the London dispersion force.
Therefore, the correct answer is (C).