As the disordemess or randomness of particles in a system increases, its entropy increases. Hydrogen is gas so disordemess or randomness is maximum in hydrogen and therefore, the entropy is highest in entropy. While water and mercury are liquid and graphite is solid so randomness decreases and entropy also decreases. The order of entropy in gaseous, liquid and solid state is as Entropy (gas) > entropy (liquid) > entropy (solid)
The property of a system which measures the degree of disorder or randomness in the system is called entropy. It is expressed by symbol S.