What allows a gas to fill a container?

A. the shape of the particles in a gas

B. the size of the particles in a gas

C. the constant motion of the particles in a gas

Answer: Option (A) is the correct answer.

Explanation:

It is known that particles of a gas are held by weak Vander waal forces, therefore, there is no force of attraction between gas molecules.

As a result, these particles are in random motion.

Thus, we can conclude that out of the given options, the constant motion of the particles in a gas allows a gas to fill a container.