volume_mute

Why does a balloon filled with helium gas rise upward through the surrounding air atmosphere?

publish date: 2026/05/20 22:17:28.912479 UTC

volume_mute

The weight of the displaced air is greater than the combined weight of the balloon envelope and the helium inside.

Helium molecules possess negative mass and are naturally repelled by Earth's gravity.

The balloon structure completely eliminates the effects of atmospheric pressure.

Helium gas generates a miniature vacuum inside the balloon envelope that pulls it upward.

Correct Answer

The weight of the displaced air is greater than the combined weight of the balloon envelope and the helium inside.

Explanation

Because helium gas is less dense than standard air, a balloon filled with helium weighs less than an equal volume of ambient air. Therefore, the upward buoyant force (the weight of the displaced air) exceeds the total downward gravitational weight of the balloon system, resulting in a net upward force.

Reference

Basic Physics: A Self-Teaching Guide

Quizzes you can take where this question appears

Buoyancy in gases