Which gas is commonly used to fill party balloons so that they float in the air?

Explanation

Helium is used to fill floating balloons because it is significantly less dense than air, causing helium-filled balloons to rise. It is also non-flammable, unlike hydrogen, which was historically used but posed serious fire risks, as demonstrated by the Hindenburg disaster. Helium is a noble gas, meaning it does not react chemically with other substances. Explore more Everyday Science MCQs on mcqstutor to keep practicing.