IF ILET A BALLOON GO, HOW HIGH CAN IT GET BEFORE IT POPS?
At sea level there’s about one tonne of pressure exerted on you by the air at all times. This pressure comes from the 60 miles of air above weighing down the air below. As helium balloons rise, the atmospheric pressure drops as there’s less air, causing the balloon to expand. This will continue until either the gas inside the balloon is of equal density to the air outside the balloon, or it pops due to the latex not being able to stretch any more.