Krypton physical properties

The extremely nonpolar character of PFCs and very low forces of attraction between PFC molecules account for their special properties. Perfluorocarbons bod only slightly higher than noble gases of similar molecular weight, and their solvent properties are much more like those of argon and krypton than hydrocarbons (2). The physical properties of some PFCs are Hsted in Table 1. 

Pure Elements. AH of the hehum-group elements are colorless, odorless, and tasteless gases at ambient temperature and atmospheric pressure. Chemically, they are nearly inert. A few stable chemical compounds are formed by radon, xenon, and krypton, but none has been reported for neon and belium (see Helium GROUP, compounds). The hehum-group elements are monoatomic and are considered to have perfect spherical symmetry. Because of the theoretical interest generated by this atomic simplicity, the physical properties of ah. the hehum-group elements except radon have been weU studied. 

The physical properties of argon, krypton, and xenon are frequendy selected as standard substances to which the properties of other substances are compared. Examples are the dipole moments, nonspherical shapes, quantum mechanical effects, etc. The principle of corresponding states asserts that the reduced properties of all substances are similar. The reduced properties are dimensionless ratios such as the ratio of a material s temperature to its critical... 

Kroll process, 13 84-85 15 337 17 140 in titanium manufacture, 24 851-853 Kroll zirconium reduction process, 26 631 KRW gasifier, 6 797-798, 828 Krypton (Kr), 17 344 commercial, 17 368t complex salts of, 17 333-334 doubly ionized, 14 685 hydroquinone clathrate of, 14 183 in light sources, 17 371-372 from nuclear power plants, 17 362 physical properties of, 17 350 Krypton-85, 17 375, 376 Krypton compounds, 17 333-334 Krypton derivatives, 17 334 Krypton difluoride, 17 333, 336 uses for, 17 336... 

Within a periodic group the physical properties vary more predictably, especially if the elements are in the same physical state. For example, the melting points of argon and xenon are 189.2°C and 111.9°C, respectively. We can estimate the melting point of the intermediate element krypton by taking the average of these two values as follows ... 

Occurrence, extraction and uses Physical properties Compounds of xenon Compounds of krypton and radon... 

Values extracted and in some cases rounded off from those cited in Rabinovich (ed,), Thermo physical Properties of Neon, Argon, Krypton and Xenon, Standards Press, Moscow, 1976, This source contains values for the compressed state for pressures up to 1000 bar, etc, t = triple point. Above the solid line the condensed phase is solid below it, it is liquid. The notation 5,646,-4 signifies 5,646 x lO"", At 83,8 K, the viscosity of the saturated liquid is 2,93 x 10" Pa S = 0.000293 Ns/m. This book was published in English translation by Hemisphere, New York, 1988 (604 pp,),... 

The maximum authorized filling limit for neon, krypton, and xenon in approved types of cylinders is the marked service pressure of the cylinder at 70°F (21.1°C) (or, in the case of specification 3 A and 3AA cylinders meeting additional specified requirements, 10 percent in excess of the marked service pressure). Because commercial grades of xenon deviate markedly in physical properties from the ideal gas at elevated pressures, maximum filling limits for the specific commercial grade of xenon being used must be determined experimentally. 

Ott U (1993) Physical and isotopic properties of surviving interstellar carbon phases. In Protostars Planets III. Levy Hand Lunine JI (eds) University of Arizona Press, Tucson, p 883-902 Ott U (1996) Interstellar diamond xenon and timescales of supernova ejecta. Astrophys J 463 344-348 Ott U, Begemann F, Yang J, Epstein S (1988) S-process krypton of variable isotopic composition in the Murchison meteorite. Nature 332 700-702... 

Properties. — For the principal physical constants sec Table VII, page 21. The density of krypton was determined 1 from the purest material obtained by tlm fractionation of 120 tons of liquid air. From the data obtained a liter of krypton weighs 3.708 grams. The molecular weight is therefore calculated to have the. value 82.92. 

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