Here's why gas molecules are far apart:

* High kinetic energy: Gas molecules have a lot of kinetic energy, meaning they are constantly moving and colliding with each other. This movement keeps them spread out.

* Weak intermolecular forces: The forces of attraction between gas molecules (like Van der Waals forces) are very weak. This allows them to easily overcome these forces and move freely.

* Compressibility: Gases are highly compressible, meaning you can squeeze them into a smaller space. This is because there is a lot of empty space between the molecules.

In summary: Gas molecules are far apart due to their high kinetic energy, weak intermolecular forces, and compressibility.