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Hydrogen is the lightest element, and is by far the most abundant in
the universe. Even with its small weight, hydrogen takes up about 90% of
the universe in weight. Hydrogen, in the form of water, is essential to life
and is present in all organic compounds. The atomic symbol of hydrogen is H,
and its atomic number is 1. Its atomic weight is 1.00797 (7). |
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In 1766, Henry Cavendish, the discoverer of nitrogen, discovered hydrogen in London England. Its name came from the Greek words 'hydro" meaning water and 'genes' meaning generator. Earlier, Robert Boyle published a paper entitled: "New experiments touching the relation betwixt flame and air'. This paper dealt with the reaction between iron fillings and dilute acids, which release hydrogen. Deuterium gas (H2, often written D2), made up from deuterium, a heacy isotope of hydrogen, was discovered in 1931 by Harold Urey, a chemistry professor at Chicago and California.
The many uses of hydrogen include the following: commercial fixation of nitrogen from the air in the Haber ammonia process, hydrogenation of fats and oils, methanol production, and hydrodealkylation, hydrocrackirg, and hydrodesulphurization, rocket fuel, welding, production of hydrochloric acid, reduction of metallic ores, filling balloons, and liquid H2 is important in cryogenics and in the study of superconductivity since its melting point is only just above absolute zero. One of hydrogen's isotopes, tritium (H3) is radioactive. This is produced in nuclear reactors and is used in the hydrogen bomb. It is also used as an agent in making luminous paints, and as a tracer isotope.
Hydrogen has many compounds, and its abundance brings out even more. Hydrogen fluoride has a formula weight of 20.006, and hydrogen chloride, or hydrochloric acid, has a formula weight of 36.461. Hydrogen bromide's weight is 80.912, and hydrogen iodide sports a formula weight of 127.912. Water, or hydrogen oxide, weighs in at 18.015, and a similar compound, hydrogen peroxide, is 34.015. Hydrogen in its gaseous state (H2) sports a weight of 2.016. This diatomic state of hydrogen is the form it takes when not in a compound.
