Why are soap bubbles always round?
Show answer & explanation
Answer: Surface tension minimizes area
Wind shapes them into spheres — Wrong. Wind doesn't shape bubbles—in fact, wind can distort or pop them. Bubbles form spheres due to surface tension, even in still air.
Surface tension minimizes area ✓ — Correct! Surface tension in the soap film pulls it into the shape with the smallest surface area for its volume - a sphere. Every point on a sphere is equidistant from the center, creating equal tension throughout. This minimizes energy, making spheres the most stable bubble shape!
Soap molecules form circles — Wrong. Soap molecules don't form circles. They create a thin film with surface tension. It's this surface tension that pulls the bubble into a sphere, not the arrangement of individual molecules.