nothing

3. 1.Hydrogen is a colourless $ odourless
gas. It is highly combustible $a source of
energy.
2.In normal state hydrogen is lightest of
all gas.

4. Hydrogen is very stable in normal condition , it is
undergoes various reaction at elevated
temperature . When it mixed with Oxygen it
gives 29,000 calories per gram ,but in coal gives
7800 calorie per gram energy.

5.  Breaking down the hydrocarbon (mainly
methane)
 Electrolysis from water.
 By reacting water of metals.

6. Bio-photolysis – The production of hydrogen from
water with the help of sunlight .

7.  Hydrogen is colourless & odourless and non
polluting , yielding pure water vapour as
exhaust when combusted in air .
 Hydrogen is the lightest chemical element and
has the best energy to weight ratio of any fuel.
 Hydrogen can be produced anywhere , it can
be produced domestically from the
decomposition of water .

8.  Hydrogen is difficult to handle , store , and
transport .it requires heavy , cumbersome tanks
when stored the gas .
 It is impossible to obtain hydrogen gas without
expanding energy in the process.
 Other than some volcanic emanations ,
hydrogen does not exist in it pure form in
environment .