Why is helium better to use in balloons?
Although Hydrogen is one on the element scale, Helium is a preferred gas to use in balloons because it is a safer (not flammable) gas than hydrogen.
Hydrogen, until the Hindenburg,then everyone realized that "Hey, Hydrogen isn't that safe to use!" Hot air balloons, you mean?? Just air that is hot. Actual hand balloons and such? Helium or again, just air. Helium floats better because it is lighter than the surrounding air around it. Helium and air are still used in both.
One of the reasons why helium balloons go down so quickly is that the helium atom is VERY TINY - much smaller than oxygen molecules or nitrogen molecules. The helium atoms are tiny enough to leak right THROUGH the material of a latex balloon. Silver "mylar" balloons hold in the helium much better, and stay inflated longer.