Why will a balloon filled with helium float in the air? A. Helium is denser than air b. Helium is less dense than air c. Helium is as dense as air d. Helium is a diatomic molecule

Answer 1

B. Helium is less dense than air

Helium is a lighter gas than the nitrogen and oxygen that make up the majority of Earth's atmosphere. The buoyant force acting on the helium-filled balloon is greater than the gravitational force pulling it down, allowing it to float in the air.