Which is an example of a liquid?

Acetone is classified as a liquid at room temperature and is commonly used as a solvent in various applications. It has a well-known characteristic of being a clear, colorless liquid that evaporates quickly, which is why it is frequently utilized in nail polish remover and other chemical processes.

On the other hand, hydrogen is a gas at room temperature, while calcium carbide is a solid compound. Chlorine, although it can exist in various states, is typically found as a gas under standard conditions. The distinction lies in the physical state of matter, where acetone maintains its liquid form, making it the correct choice among the options presented.