Intermolecular forces explain melting point trends in halogens Steps: - Chlorine (Cl₂) and iodine (I₂) are nonpolar diatomic molecules held by weak intermolecular forces. - Melting points depend on the strength of these forces, not intramolecular bonds. - Van der Waals (London dispersion) forces strengthen down Group 17 due to increasing atomic size and electron count. - Larger I₂ molecules induce stronger temporary dipoles, requiring more energy to melt than smaller Cl₂. Why D is correct: - D states that iodine's larger molecular size leads to stronger London dispersion forces, directly increasing its melting point relative to chlorine, as defined by the inverse relation between polarizability and molecular size in nonpolar substances. Why the others are wrong: - A: More electrons contribute to forces, but the statement overlooks that Cl₂ also has van der Waals forces; it doesn't fully explain the trend without size. - B: Covalent bonds are intramolecular and affect boiling points more; I-I bonds are actually weaker than Cl-Cl bonds due to poor overlap in larger orbitals. - C: Size alone doesn't specify the type of force; …