Helium

what'/ the u/e? Alton Banks ... However, credit for thediscovery ... Banks, A. J. “The Periodic Table Videodisc”, JCE: Software 1989, Special Issu...
6 downloads 0 Views 455KB Size
whcrt5 the we? Helium Symbol: HE Ammic number: 2 Atomic weight 4.00260 Melting point: 0.8 K (26 atm) ~oi~in point: g 4.2 K Density: 0.0002

EEEmaB The first report of helium's existence was that of Janssen in 1868 when he noticed a new lme in a solar s~ectrum taken during an eclipae. Lockyer and Frankland suggested the name helium (GI. helios, the Sun). However, credit for the discovery of helium usually goes to Ramsay who found the element in the uranium-containing mineral, clevite. Helium is one of the most abundant elements in the universe, second only in abundance to hydrogen. Found in great profusion in the stars in which it is a product of the

ALTON BANKS saahwt T e r n State University San Marcos. TX 78666

energy-producing fusion reactions, helium was rare until the discovery of helium-rich wells in the Southwest. The bulk of the free world's supply of helium is now found in these wells in Texas, Oklahoma, and Kansas. Following the discovery of these wells, the price of the gas plummeted from $2500/ft3in 1915to 1.5 cents/ft3 in 1940 and is now about 15 cents/ft3. Helium's uses are predicated on its low density and its chemically inert nature. A large percentage of the current applications of helium (33%)are in cryogenics. About 20%of the applications of helium are in welding and industrial applications. Mixtures of helium and oxygen are used in tanks for underwater breathing devices. A small percentage (4%) of its uses are as a lifting gas. Helium has also found a use in lasers. Some of these applications are shown on "The Periodic Table Videodisc" in frames 36303-36320. Sources "KC? Di-emx Exploring ths Pmpertie of the Chemiesl Elements"; JCE: Software ass, le(1). Banks.A. J. "ThePrriodieTableVidedsc",JCE:SofluwD 1989. Speiallmue 1. Hondbmk of Chemist?? & Physics, 52th ed.: Wcast, Robert C.; Cbemid Rubber: Ckveland, OH, 1971-1972, p 5 1 5 . K i r k - 0 t h Coneire ~ Eneyclopedio of Chemical Technolqgy;Interaeionee: New York, 1985: pp5SSffi.

Volume 66 Number 11 November 1989

945