The discussion centers on the correct naming of a molecule with a three-carbon chain and a double bond. The consensus is that the correct name is propene, as the prefix "1-" is unnecessary. The term "methylethene" is clarified to be incorrect, as it does not accurately represent the structure. The conversation also touches on "2-methylpropene," which has four carbons and is also known as isobutylene. The participants emphasize the importance of proper nomenclature in organic chemistry and provide a reference link for further information.