The element hydrogen is the lightest of all elements and is not normally found in an uncombined state on the earth, but is found in a number of compounds. Due to this hydrogen must be purified for our usage. Hydrogen is used in many different ways in today"s society but must be used with caution due to its flammability. Hydrogen is thus called because water is generated, or born, by the combustion of hydrogen. .
Hydrogen's physical state is that of a gas. Though hydrogen is rarely found free in nature it is present in a large amount of compounds. Hydrogen is found in oil and gas wells, earth's atmosphere, water, earth's crust, and in many other places. To compensate for the fact that hydrogen is rarely found in it's free, pure, form in nature methods of purification have been developed. One of the most popular of these methods is pressure-swing absorption (PSA). This method works by absorbing impurities from hydrogen rich gas. Another method that is used is called the Bosch process. In this method steam is passed over very hot iron-filings, the iron combines with the oxygen in steam and hydrogen gas is separated. .
Hydrogen is a useful tool in our society today. We use hydrogen in jet fuel, the production of ammonia, conversion of oils into solid fats (margarine), and the refining of metals. Hydrogen was once used in blimps and balloons but was abandoned because of if it's flammability (the explosion of the Hindenburg.) According to a hazards identification system developed by the National Fire Protection Association, hydrogen can be harmful to one's health and is also very flammable. The system has rates from 0-4 (0 being no harm and 4 being very harmful). For health risks hydrogen rated at one and for flammability it rated very high at four. Hydrogen is very useful but can also be dangerous. .
Henry Cavendish is widely accredited with the discovery of Hydrogen in the year 1776. Cavendish, during an experiment, collected gas above mercury and studied it and proceeded to report his findings that hydrogen is a distinct substance.
