Hydrogen is less dense than Helium. Yet, Helium is used to keep balloons and blimps aloft. Why?

1 Answer
Jan 25, 2017

Compare the reactivity of #"dihydrogen"# versus #"helium......"#

Explanation:

And consider the fate of the Hindenburg LZ 129 when it was struck by lightning.

#H_2(g) + 1/2O_2(g) rarr H_2O(l) + Delta#

Can helium be oxidized likewise?