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Question
How would you show that hydrogen is lighter than air?
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Solution
Take a delivery tube and place one of its ends in a soap solution kept in a trough and the other one in a flat bottom jar as shown in the figure. The soap bubbles containing hydrogen rise upward the air. The rising soap bubbles prove that hydrogen is lighter than air.
Hydrogen-filled soap bubbles rising upward in the soap solution and into the air shows that hydrogen is lighter than air.
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