Title: Neon
CAS Registry Number: 7440-01-9
Literature References: Ne; at. wt 20.1797; at. no. 10. Group VIIIA (18), also known as Group 0. A noble gas characterized by an electronic structure in which the outer p subshell is entirely filled. Naturally occurring stable isotopes (mass numbers): 20 (90.51%); 21 (0.27%); 22 (9.92%); known artificial radioactive isotopes: 16-19; 23-25. Longest-lived known isotope: 24 (T½ 3.38 min, b-emitter). Abundance in igneous rock of the earth's crust: 7 ´ 10-5 ppm by wt; concentration in air: 18.2 ppm by vol. Obtained commercially from the atmosphere by distillation-liquefaction process. Discovered in 1898 by Travers and Ramsay: The Discovery of the Rare Gases, London, 1928. Monograph: Argon, Helium and the Rare Gases vols. 1, 2, G. A. Cook, Ed. (Interscience, New York, 1961) 818 pp. Reviews: Cockett, Smith, "The Monatomic Gases" in Comprehensive Inorganic Chemistry vol. 1, J. C. Bailar, Jr. et al., Eds. (Pergamon Press, Oxford, 1973) pp 139-211; S.-C. Hwang, W. R. Weltmer, Jr. in Kirk-Othmer Encyclopedia of Chemical Technology vol. 13 (John Wiley & Sons, 4th ed., 1995) p 1-38; Chemistry of the Elements, N. N. Greenwood, A. Earnshaw, Eds. (Pergamon Press, New York, 1984) pp 1042-1059. Review of use in inductively coupled plamsa-mass spectrometry: S. F. Durrant, Fresenius J. Anal. Chem. 347, 389-392 (1993).
Properties: Colorless, odorless, tasteless, monatomic, inert gas; will form compds with highly electronegative elements such as O, F, Cl. Does not condense at the temp of liq air; solid at the temp of liq hydrogen; the solid form exists as face-centered cubic crystals at normal pressure. Soly of gas in water (20°): 10.5 cm3/kg water. Triple pt temp 24.562 K, press 43.37 kPa. Critical temp 44.40 K, critical press 2654 kPa, critical d 483 kg/m3. Gas: d0 (101.3 kPa) 0.89994 kg/m3, d (normal bp) 9.552 kg/m3. Liquid: normal bp -246.048°, d (normal bp) 1207 kg/m3, d (triple pt) 1247 kg/m3, heat of vaporization (normal bp) 1.741 kJ/mol. Solid: d (triple pt) 1444 kg/m3, heat of vaporization (triple pt) 2.139 kJ/mol, heat of fusion (triple pt) 0.335 kJ/mol. Emission spectra: T. Jacksier, R. M. Barnes, Appl. Spectrosc. 48, 65 (1994).
Boiling point: bp -246.048°
Density: d 483 kg/m3; d0 (101.3 kPa) 0.89994 kg/m3; d (normal bp) 9.552 kg/m3; d (normal bp) 1207 kg/m3; d (triple pt) 1247 kg/m3; d (triple pt) 1444 kg/m3
CAUTION: Can act as a simple asphyxiant by displacing air. See: Matheson Gas Data Book (Matheson Co., Inc., 4th ed., East Rutherford, NJ, 1966) pp 359-361.
Use: Gas in neon light tubes; ingredient of gaseous fillers for antifog devices, warning signals, electrical current detectors, high-voltage indicators for high-tension electric lines, lightning arresters, wave-meter tubes; in Ne-He lasers; in mixtures with He and Ar in Geiger counters. Liquid as cryogen to produce low temps. |