Properties distinguishing ethene monomer from polyethene polymer Steps:

• Empirical formula of ethene is CH₂; polyethene repeats -CH₂-CH₂- units, so also CH₂.
• Ethene is flammable gas; polyethene is solid plastic that burns but isn't typically a fuel source.
• Van der Waals forces depend on molecular size: small ethene molecules have weak forces (low boiling point, -104°C); long polyethene chains have strong forces (melts at ~115°C).
• Opposite of C would mean stronger forces in monomer, which contradicts molecular size effect.

Why C is correct:

• Van der Waals forces strengthen with increased surface area for interactions; polymers' long chains provide more contact than small monomers, per intermolecular force principles.

Why the others are wrong:

• A: Both share empirical formula CH₂, unchanged in addition polymerization.
• B: Polyethene can be combusted as fuel in waste-to-energy processes, though not conventional like gaseous ethene.
• D: Monomer's forces are weaker, not greater, due to smaller size.

Final answer: C