whcrt5 the we? Hydrogen Symbol: Atomic number: Atomic weight: Melting point: Boiling point:
H 1 1.01 14.1 K 20.4 K
Elemental hydrogen is a colorless, odorless, tasteless gas (at room temperature). Its first characterization is credited to ~aracelsu; (late 15th century) who said that when iron and sulfuric acid interact "an air arises which bursts forth like the wind". Cavendish discovered "inflammable air" in 1766,' and was able to prove-in 1781-that water was the sole product of the reaction of hydrogen with oxygen. In 1783 Lavoisier named the gas hydrogen-from the Greek word
' "KC?: Exploring the Chemical Elements"; X E Software 1988,
im11 .-\ .,.
2Banks, A. J. "The Periodic Table Videodisc"; JCE: Software 1989, Special Issue 1. Wandbook of Chemistry 8 Physics. 47th ed.; Chemical Rubber: Cleveland. OH, 1966. Kirk-Othmer Encyclopedia of Chemlcal Technology, 2d ed.; In-
ALTON BANKS Souihwest Texas State University San MBTcos, TX 78666
meaning "water producer". Abundant in stars, it is most important in the proton-proton fusion reactions that occur. However, the free element on earth is present at a level sliehtlv- less than 1Dom. The most abundant element in the universe, hydrogen bccurs chiefly in water and manifold hvdrocarhon compounds. The free element-continuallv escaping into spat-is replaced via coal deposits, vol&ic gases, and decay of organic matter. Perhaps the best-known uses of hydrogen are attributable to its low densitv. The demise of the Hindenhure in 1937bringing to an end hydrogen's use in lighter-than-air craftand of the shuttle Challenger in 1986 mark with areat claritv the reactive nature of hydrogen with oxygen. ~ h e s applicae tions are found on the Periodic Table Videodisc2 on frames 36291-36302. Other very important utilizations of hydrogen involve the production of ammonia-via the Haher process-and of methanol-from hydrogen and carbon monoxide. The production of ammonia accounts for more than two-thirds of the hydrogen used in the world. The petroleum industry accounts for a third imoortant area in which hvdroeen is . utilized. Atomic hydrogen is used for welding certain alloys. Additionallv the element-with a meltina and boiling ooint close to absolute zero--has been employed in superc%ductivity ~tudies.3,~
This miumn will describe certain uses or applications of the elemenk. h will not be an exhaustive treatise. but will poim out some of Um interesting ways in whlch we employ the elements andlor their como~nds.k each case. a reference to the locations of these BppiiCationS on ''The Perodic Taole Vvaecdisc' wli oe given. 'The Pellcd c TaDie Vrdeodire" may oe ootalned ham X E : SoHware. Deparimem of Chem.stry. Univsrsily of Wisconsin. Maoism. W 53706
terscience: New York.
Volume 6 6
Number 10 October 1969