The sun is basically a giant ball of hydrogen and helium gases. In the sun's core, hydrogen atoms combine to form helium atoms. This process—called fusion — gives off radiant energy.
Hydrogen is the element with the atomic number of 1 and symbol H. In conditions of standard pressure and temperature, the gas is colorless, odorless, nonmetallic, tasteless, diatomic and highly flammable. It has an atomic mass of 1.00794 g/mol making it the lightest element. It is also the most commonly found chemical element, making up close to three quarters of the universe's elemental mass. Stars found within the main sequence of the universe mainly constitute hydrogen in its plasma state. The most commonly found isotope of hydrogen, also known as protium, consists of just one proton and no neutrons. When forming ionic compounds hydrogen can take two forms. Either it takes the role of a positive charge and thus becomes a cation composed of a bare proton. Or on the other it take the role of a negative charge turning in to an anion known as a hydride. Hydrogen easily forms compounds with most other elements and is present in water and most organic compounds.
 Sources of Hydrogen
Within the universe hydrogen is primarily found in the stars, and plays an integral role in keeping the universe going by taking part in the proton-proton reaction and carbon-nitrogen cycle. Stellar hydrogen fusion processes give out very large amounts of energy by combining hydrogen resulting in the formation of helium. Hydrogen is also produced through numerous industrial processes such as steam on heated carbon, decomposition of certain hydrocarbons with heat, reaction of sodium or potassium hydroxide on aluminum electrolysis of water, or displacement from acids by certain metals.
Industries require large amounts of hydrogen as it is used for nitrogen fixation using the Haber ammonia process, as well as for the hydrogenation of fats and oils. Large quantities are also required for methanol production, in hydrodealkylation, hydrocracking, and hydrodesulfurization. Other uses include rocket fuel, welding, producing hydrochloric acid, reducing metallic ores, and filling balloons. The Hydrogen Fuel cells are a developing technology that is seen to be one of the best upcoming alternative fuel solutions. Pollution-free hydrogen could replace natural gas, gasoline, etc. Liquid hydrogen is essential in the field of cryogenics as well as in the field of superconductivity, as hydrogen melts at only 20 degrees above absolute zero.
 Did You Know?
- Hydrogen gas is lighter than air and, as a result, it rises in the atmosphere. This is why hydrogen as a gas (H2) is not found by itself on earth.
- Hydrogen has the highest energy content as compared to any other common fuel by weight(about three times more than gasoline), but the lowest energy content by volume (about four times less than gasoline).
- Like electricity, hydrogen is an energy carrier and must be produced from another substance.
- Steam reforming is currently the least expensive method of producing hydrogen and accounts for about 95 percent of the hydrogen produced in the United States. The process however releases greenhouse gas.
- Though electrolysis releases no emissions while splitting hydrogen from water, it is an expensive process.
- There are currently about 200 hydrogen-fueled vehicles in the United States – mostly in California.
- Environment Words- A Dictionary in Plain English, published By Images Asia
- Energy Kids Page : Hydrogen