How long would a latex balloon filled with hydrogen last?

No. The hydrogen atom is even smaller than the helium atom. So it would definitely not last longer. My guess is that it would probably be about the same, or slightly shorter.

@HungryGuy That’s what I thought.

Considering the amount of static generated by latex balloons and the volitilty of hydrogen, I doubt you will find very many people willing to conduct the experiment.

But given the size of the relative atoms, it should take less time for hydrogen to escape the balloon than helium.

Good point. So would there be a decent chance of the hydrogen igniting from the static the latex generates?

@intro24 Virtually none. It would need to spark and it would need to be more significant that anything from a baloon.

All these answers are wrong. I don’t know the answer, but the logic being presented is flawed terribly.

Merely comparing the sizes of the respective atoms misses the mark for two reasons.

One, the relative velocities (mean free path) for the particles is a function both of the molar mass, and of the cross-section of the particles (respectively).

Two, hydrogen almost never occurs as a mono-atomic moiety as a gas. We’re really comparing the size (cross-section), reactivity (adsorption) on the surfaces of the rubber, and mass of the diatomic hydrogen to the mono-atomic helium…

These two factors are at odds (have a mutually counteracting effects) to each other, so I can’t predict on base principles (without experimentally-derived parametric formulas) which will last longer in a balloon. Sorry, guys.

Ok, everybody. I’ve made the experiment: I filled a balloon with hydrogen gas. And it completely deflated over a night. That was 3–4 times faster than with helium-filled balloon.