To subscribe to this question you need to
sign in to the AnswerBank or register
if you are not already a member. All you need is a valid email address to register.
1 to 4 of 4
gen2 Mon 12/11/07 21:23
In two words: Yes, both.
The gas inside the balloon is at a higher pressure than the air outside and helium atoms are the second smallest, only beaten by hydrogen - but whereas helium gas is made up of atoms, hydrogen is diatomic and goes around as molecules of H2.
The helium atoms easily diffuse through minute pores in the rubber membrane of the balloon.
squarebear Tue 13/11/07 08:13
gen2 is quite right. This is why most helium balloons are made of metal foil as it's harder for the helium to pass through the surface.
voyager1970 Thurs 22/11/07 10:43
I agree with the size issue, but the pressure of the gas inside the balloon must be the same as the pressure outside. If the pressure is higher inside the balloon would explode!
floggedhorse Fri 23/11/07 20:36
Sorry to disagree - but surely the pressure in the baloon is greater than the pressure outside - it has to overcome the restrining force of the baloon material!