Chapter 4.3, Problem 4.8P

(a)

Interpretation Introduction

Interpretation:

The species $\left({\text{CH}}_{\text{4}}\text{,}{\text{C}}_{\text{3}}{\text{H}}_{\text{8}}\right)$ with stronger London dispersion forces has to be given.

Concept introduction:

London Dispersion forces:

London dispersion forces are weak interactions due to the temporary changes in electron density in a molecule.  All covalent compound exhibits London dispersion forces.  These intermolecular forces are the only intermolecular forces present in nonpolar compounds.

(b)

Interpretation Introduction

Interpretation:

The species $\left(\text{He,}\text{Ne}\right)$ with stronger London dispersion forces has to be given.

Concept Introduction:

Refer to part (a).