Helium balloons float in water because of the force called buoyancy, which is the upward force exerted by water that resists the weight immersed in the liquid. A balloon with helium gas is lighter than a balloon filled with air because a litre of air weighs 1.25 grams but a litre of helium gas weighs only 0.18 gram. To under-stand the physics of the helium balloon and the water, let’s take a balloon, which is 1 foot in diameter. This balloon will hold approximately half a cubic foot of helium and, therefore, will weigh about 14 grams that is less than a balloon of 30 centimetre having air. Balloons usually float because air is lighter than water. But because helium gas is lighter than air, the balloon with helium gas floats on the water upwards and pops up even though you add weight with the balloon.
Why do Helium Balloons Float?
