Table of Contents (click to expand)What Are Bubbles?Why Are Bubbles Round? Bubbles are round because the surface tension of the soap film pulls them into the shape of a sphere. This happens because the surface tension is the force that balances the inward force of the air molecules on the bubble and the outward force of the air molecules on the bubble. In the case of bubbles, the air molecules trapped inside experience a force from the air molecules outside the bubble. They, in turn, also exert an equal and opposite force. Due to this, the air bubbles inside try … Continue reading Why Are Bubbles Round?