Question

why does a gas fill in a vessel completely?

Answer 1

HEYA!!

Becoz The force of attraction between particles of gas is negligible. Because of this, particles of gas move in all directions. Thus, a gas fills the vessel completely in which it is kept. ... Because of this a gas exerts pressure on the walls of the container in which it is kept.

Answer 2

because the gases have very less intermolecular forces between their molecules nd also have high kinetic energy .....Thats why the gases fill up the container it is stored in...