Helium has one more proton than hydrogen
a particle of hellium is small enough to fit in between the molecules of latex (or whatever the balloon is made of) and eventually leaks out due to diffusion. If the environment the balloon is in has the same amount of hellium in it as the balloon, it won't deflate.
one
Hydrodgen and Oxygen.
Hellium
No. Helium does not burn.
hellium
4
2
hellium is a gas that makes light objects float e.g. balloons
helium
hellium
hellium