It is about 6 x 10^23. So in 5 moles of oxygen gas, which has a mass of 5x16=80 grams, there are 5x6x10^23 = 30x10^23 molecules.
<span>These gas molecules are much smaller than the distance between them.
</span><span>So, most of the volume of a gas is therefore empty space.
</span><span>There is no force of attraction between gas particles or between the particles and the walls of the container.
Because there is a large amount of empty space between gas molecules,the gas has property of low density.</span>