Question

of two diatomic elements are listed in the table shown. substance cl₂ i₂ boiling point (k) 239 457 which statement best explains the observed difference in the boiling points? a iodine has the larger electron cloud, so molecules of i₂ are more polarizable. b iodine has the lower electronegativity, so molecules of i₂ are more polar. c chlorine has the smaller atomic radius, so molecules of cl₂ contain weaker bonds. d chlorine has the higher electronegativity, so molecules of cl₂ are more polar.

Explanation:

The boiling - point difference between $Cl_2$ and $I_2$ is due to London dispersion forces. Larger molecules with more electrons have larger electron clouds and are more polarizable, leading to stronger London dispersion forces and higher boiling points. Iodine ($I_2$) has a larger electron cloud compared to chlorine ($Cl_2$) because iodine atoms are larger and have more electrons. This makes $I_2$ molecules more polarizable and results in stronger intermolecular forces and a higher boiling point.

Answer:

A. iodine has the larger electron cloud, so molecules of $I_2$ are more polarizable.