What are the advantages of using hydrogen as a fuel?

Explanation

Hydrogen has the following advantages over conventional fuels such as coal, ketrosene, petrol etc.
(i) Its combusion is alays complete and there are no unburnt particles. Thus, it can solve all pollution problems which are major threat to modern civilisation.
(ii) Hydrogen has more calorific value than petrol and other fuels. For example 9-5kg of liquid of hydrogen can evolve as much energy on combustion as 25kg of petro.
(iii) In space rockets, liquid hydrogen gives higher upward thrust as compared to other fuels.