why does helium diffuse out of containers ???

Answer 1

the atoms of helium are 4 times faster than air (oxygen/nitrogen mixture), moreover helium doesn't react with anything at standard conditions (100000 Pascals, 25°C)

That means it can pass throught the walls of a sealed container, made for example from PET plastic. (the one used for water)
air and CO2 can pass throught the plastic too, but they are much much slower.

Answer 2

This is usually a result of a couple things. First, it is usually pressurized in the container, and all gases when under pressure will diffuse when a hole is made giving it access to atmospheric or lower pressure. This is the nature of gases - to go to the lowest possible energy state, which means uniform pressure.

Second, all air moves, so even if it wasn't helium, it would diffuse out of a container eventually, because gases randomly move around. But, since helium is lighter than air, it will diffuse faster than say, oxygen would, because it is less dense and therefore will naturally rise above the normal air as the denser, heavier gases "push" it out of the way on their way down.

Answer 3

It doesn't diffuse out of all containers.
It will diffuse through the walls of a rubber balloon because the helium molecules are smaller than oxygen etc.
Mylar contains it and other materials used in dirigibles won't allow diffusion.

Answer 4

Hi,
Because it is a very small, light molecule having approximately 4 for atomic weight as compared the approximate atomic weights of 16 for oxygen, 14 for nitrogen, 10 for neon, 18 for argon, etc.

Hope this helps.
FE

Answer 5

It's small, does not interact strongly with anything and has a high velocity.

Answer 6

it's lighter than air