Which substance is a solid at room temperature?

Which substance is a solid at room temperature?

• A. Acetone
• B. Chlorine gas
• C. Gasoline
• D. Magnesium

Answer: (D)

At room temperature, whether a substance is a solid depends on its melting and boiling points relative to typical room conditions (about 20–25 °C). Magnesium has a melting point around 650 °C, far above room temperature, so it remains a solid in everyday conditions. The other substances are liquids or gases at room temperature: acetone boils at about 56 °C, so it is a liquid; chlorine has a boiling point around -34 °C, so it is a gas; gasoline is a liquid because its components have boiling points around or above room temperature.

At room temperature, whether a substance is a solid depends on its melting and boiling points relative to typical room conditions (about 20–25 °C). Magnesium has a melting point around 650 °C, far above room temperature, so it remains a solid in everyday conditions. The other substances are liquids or gases at room temperature: acetone boils at about 56 °C, so it is a liquid; chlorine has a boiling point around -34 °C, so it is a gas; gasoline is a liquid because its components have boiling points around or above room temperature.