Helium, being lighter than the other elements in our atmosphere, rises. It's the same when air is heated inside a hot air balloon, making it less dense per volume inside the balloon than it is ...

The secret to understanding why the balloon moves this way is looking at why it flies in the fist place. Helium balloons are filled with a substance that is less dense than air (or at least less ...

The helium shortage is potentially deflating for a range of purposes: airbags, rocket fuel, MRIs, fiber optics, semiconductors, and, yes, balloons.

Introduction Turn a pile of trash into a toy car—and watch it go! In this activity you will learn some physics concepts and use recycled materials to build a toy car that is propelled by a balloon.