Answer:
Air
Explanation:
Matter exists in three states namely; solid, liquid and gas. These three states contain molecules/particles that behave differently from one another. The particles of gas are scattered in such a way that they move randomly in a fast motion. This causes the ability of gas particles to diffuse in an open space i.e. spread quickly
In the options of materials given in this question, AIR represents a gaseous substance, hence, it is made up of particles that move rapidly in a random manner. This will cause it to spread out (diffuse) to completely fill a larger container it is placed in.