A. Nitrogen
B. Helium
C. Methane
D. None of these
🧠 Explanation:
Helium is the gas used in balloons to make them float. As a lighter-than-air gas, helium provides lift, allowing balloons to rise and stay aloft for celebrations or scientific purposes. Its low density and non-flammable nature make it safer than hydrogen, historically used but risky due to flammability. Helium’s inert properties ensure stability, making it ideal for party balloons, airships, and weather balloons. Its use is critical in various fields, though its scarcity has raised concerns about sustainable supply for future applications.
