helium
propane
carbon dioxide
nitrogen
Answer is Wrong!
Answer is Right!
The correct answer is A. Helium.
Helium is the gas used in hot air balloons because it is lighter than air. This means that when hot air is blown into a balloon, the balloon will rise because the hot air is less dense than the surrounding air. Helium is also non-flammable, which makes it safe to use in hot air balloons.
Propane is a flammable gas that is used in cooking and heating. Carbon dioxide is a gas that is used in fire extinguishers and carbonated beverages. Nitrogen
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