AP BIOLOGY

Detailed explanation-1: -Larger molecules have larger electron clouds so therefore stronger instantaneous-induced dipole bonds.

Detailed explanation-2: -In general, substances with larger molecules have stronger intermolecular forces of attraction and higher boiling points. Keep in mind, however, that compounds capable of hydrogen bonding do tend to have anomalously high boiling point.

Detailed explanation-3: -Larger and heavier atoms and molecules exhibit stronger dispersion forces than do smaller and lighter atoms and molecules. F2 and Cl2 are gases at room temperature (reflecting weaker attractive forces); Br2 is a liquid, and I2 is a solid (reflecting stronger attractive forces).

Detailed explanation-4: -Radius of molecule: Increasing the radii of the molecules decreases the space between them, causing them to run into each other more often. Therefore, the mean free path decreases. Pressure, temperature, and other factors that affect density can indirectly affect mean free path.