Hydrogen is a chemical element with chemical symbol H and atomic number 1. With an atomic weight of 1.00794 u, hydrogen is the lightest element on the periodic table.
1. Consumption in processes
Large quantities of H2 are needed in the petroleum and chemical industries.
The largest application of H2 is for the processing ("upgrading") of fossil fuels
, and in the production of ammonia.
Hydrogen is commonly used in power stations as a coolant in generators due to a
number of favorable properties that are a direct result of its light diatomic molecules.
3. Energy carrier
Elemental hydrogen from solar, biological, or electrical sources require more energy to make it than is obtained by burning it, so in these cases hydrogen functions as an energy carrier, like a battery.