3 ms·

hydrogen would probably be tougher to get their hands on for your average schoolkids.

• jrockway 18y ago
  You can make hydrogen with a glass of water and a battery. It is not hard to get.
  • noodle 18y ago
    while true, its probably easier/safer to go buy a tank of helium. and easier to get the approval of a school
  • nradov 18y ago
    That gets you hydrogen at ambient pressure. To get the hydrogen into the balloon you have to compress it at least a little bit. Running hydrogen through a compressor can be extremely dangerous if you don't have the proper equipment.
    • ars 18y ago
      Well you could always simply make it _inside_ the balloon. And it couldn't be that hard to buy a canister of compressed hydrogen. But, it's probably much much more expensive (I'm guessing 10x more), so probably not practical for students.