Question Analysis: Assertion-Reasoning type question based on the physical properties of Haloalkanes (NCERT Class 12 Chemistry, Chapter 10).

Step 1 (Governing Principle): [0.25 Mark]
The boiling point of alkyl halides is primarily governed by the magnitude of van der Waals forces of attraction. These forces are directly proportional to the size and mass of the halogen atom attached to the alkyl group ($R$). As the size of the halogen atom increases, the polarizability of the molecule increases, leading to stronger intermolecular van der Waals forces.

Step 2 (Step-by-Step Logical Deduction): [0.50 Mark]

• The size of the halogen atoms follows the order: $I > Br > Cl > F$.
• Since the alkyl group ($R$) remains constant, the molecular mass and the surface area increase as we move from $F$ to $I$.
• The strength of van der Waals forces follows the order: $RI > RBr > RCl > RF$.
• Consequently, more energy is required to overcome these forces in $RI$ compared to $RF$, resulting in higher boiling points for iodides.

Step 3 (Final Concluded Answer): [0.25 Mark]
Both Assertion (A) and Reason (R) are true, and Reason (R) is the correct explanation of Assertion (A).

💡 EL10 Concept Insight: Think of the halogen atoms like balls of different sizes; the bigger the ball (like Iodine), the stickier it is to other molecules, making it harder to pull them apart into a gas, which is why it has a higher boiling point!