Which substance is less dense, oil or natural gas?

Which substance is less dense, oil or natural gas?

• A. Water
• B. Rock
• C. Oil
• D. Natural gas

Answer: (D)

Density is mass per volume, and gases have much lower density than liquids because their molecules are spread out. Natural gas, mainly methane, is about 0.7 kg per cubic meter at standard conditions, while oil is around 800 kg per cubic meter. So natural gas is far less dense than oil. This is why gas rises in air, whereas oil—though less dense than water—is still much denser than the gas.

Density is mass per volume, and gases have much lower density than liquids because their molecules are spread out. Natural gas, mainly methane, is about 0.7 kg per cubic meter at standard conditions, while oil is around 800 kg per cubic meter. So natural gas is far less dense than oil. This is why gas rises in air, whereas oil—though less dense than water—is still much denser than the gas.