Which state of matter includes materials with a boiling point less than 68 degrees?

The correct answer is gas, as it includes materials that have a boiling point less than 68 degrees Fahrenheit. At or below this boiling point, substances exist in a gaseous state under standard atmospheric conditions. This means that they have enough thermal energy to remain in the vapor phase rather than condensing into a liquid or solid state.

In contrast, solids have defined shapes and volumes and exist at temperatures well below their melting points. Liquids occupy a specific volume but take the shape of their container, and they generally exist in a temperature range that allows them to remain as liquids, which is typically above their freezing point and below their boiling point. Aerosols, while they can contain a gaseous component, refer specifically to fine solid or liquid particles suspended in a gas and don’t align with the description of a state of matter defined solely by boiling points.

The key factor here is that gases have the ability to exist at lower temperatures where they would be in the gaseous phase, making them the appropriate choice in this question.