Bryan said in part:

Helium is difficult to contain because the gas particles are so small they
tend to diffuse through the tiny pores in rubber balloons. Because helium is a
noble gas, its atoms don't normally combine with any other atoms to form
molecules, not even other helium atoms. So helium gas is composed of individual
atoms of helium and it is the second smallest atom there is. Most other
elements form diatomic molecules in their gaseous state and any
molecule formed from two atoms is going to be much larger than a helium atom.
Hydrogen, for example, is half as heavy as helium but its gas particles are
much larger so hydrogen is easier to contain.

Keeping in mind hydrogen's explosive qualities, might it not be a better gas
for small toy balloons? I've even heard of blowing soap bubbles with hydrogen
and poking them with a lighter of some sort. Availability?

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