You can compress a gas because 1. of the enormous empty space between its particles. 2. it is composed of large particles. 3. it is composed of elements. 4. it is composed of small particles.

1. of the enormous empty space between its particles

Explanation:

Gases expand to fill the container in which it is placed leaving large space between its particles whereby they can be compressed

Matter in solid form consists of particles of that are so close together and fixed in their location. matter in liquid state are also close together, but they are more separated apart to allow free movement. The same number of particles in gaseous form, will occupy a greater volume as the gas expands to fill its container. The bonds between gaseous molecules are small so they are free to move singly, in their low weight state, whereby they can collide with each other and be projected to fill the container in which they are placed