The pressure in a closed container of gas is caused by the _ between
the particles of the gas and the walls of the container.

The pressure in the closed container is caused by the rapid movement and collisions of the gas particles within and between the container walls.

Explanation:

In gas, the molecules are not closely packed as they are randomly dispersed and when it is compressed in a container they are limited to their random movement condition which results in the collision with one another molecules.   Thus the rapid movement and collision of molecules result in the creation of the pressure build inside. the pressure is proportional to the number of molecules present in the container which decides the pressure inside the container.

Cardiac muscle causes movement in the bone.