Question
Why hydrogen filled balloon rises up and a C02 filled balloon falls down?
Solution
Hydrogen gas is lighter than air therefore, the weight of air displaced by hydrogen balloon is greater than the weight of hydrogen. Therefore, the buoyant force on the hydrogen balloon is greater than its weight and hence rises up. But CO2 is heavier than air thus, the buoyant force on CO2 balloon is less than its weight and hence it falls down.
