Which property of halogens accounts for the observed trends in physical properties such as melting point, boiling point, and dipole moment?

• A. Lipophilicity
• B. Solubility
• C. Polarizability
• D. Density

Answer: (C)

Verified step by step guidance

1. Understand the concept of polarizability: Polarizability refers to the ability of an electron cloud around an atom or molecule to be distorted by an external electric field. This distortion affects how molecules interact with each other.
2. Recognize the trend in halogens: As you move down the group in the periodic table from fluorine to iodine, the size of the halogen atoms increases, leading to greater polarizability.
3. Connect polarizability to physical properties: Increased polarizability in larger halogens results in stronger London dispersion forces, which are intermolecular forces that arise due to temporary dipoles.
4. Relate dispersion forces to melting and boiling points: Stronger dispersion forces require more energy to overcome, leading to higher melting and boiling points for larger halogens.
5. Consider dipole moments: While polarizability primarily affects dispersion forces, it can also influence dipole moments in molecules where halogens are bonded, affecting how these molecules interact with polar and nonpolar substances.