Length krypton

Wavelength equivalent of one electron volt = 1.2398 x 10 " cm Standard of length, krypton 84 red line = 6057.802106 A (adopted October 1960 by the 11th General Conference on Weights and Measures, Paris)... 

It is the most corrosion-resistant metal known, and was used in making the standard meter bar of Paris, which is a 90 percent platinum and 10 percent iridium alloy. This meter bar was replaced in 1960 as a fundamental unit of length (see under Krypton). 

In 1960, the SI unit of length was redefined. While keeping the metre as the unit of length, it is now defined as 1 650763.73 wavelengths of the light emitted in vacuo by krypton-86. This is a sensible standard, because it can be reproduced in any laboratory in the world. 

Since 1960 the wavelength of the spectral lines of the krypton-86 isotope has been used as the standard for the length of the meter. One meter is now defined as 1,650,762.73 wavelengths of the reddish-orange spectral line of the Kr-86 isotope. 

With this structure the nickel atom lias achieved the krypton electron configuration its outer shell contains five unshared pairs (in the five M orbitals) and five shared pairs (occupying the 4s4p3 tetrahedral bond orbitals). The Ni—C bond length expected for this structure is about 2.16 A, as found by use of the tetrahedral radius 1.39 A obtained by extrapolation from the adjacent values in Table 7-13 (Cu, 1.35 A Zn, 1.31 A). 

The theoretical shoulders for krypton and xenon were computed using values of aM(v) calculated by McEachran, Stauffer and Campbell (1980) and Schrader (1979) and values of Z [(v) calculated by the former. In the case of krypton, the experimental shoulder length and shape are reproduced well using the data of McEachran, Stauffer and Campbell but the results of Schrader give a much longer shoulder than is observed. For xenon, poorer agreement between theory and experiment has been found for both the shape and the magnitude of (Zef[(t)). 

The meter is the length equal to 1650763.73 wavelengths in vacuum of the radiation corresponding to the transition between the levels 2p10 and 5ds of the krypton-86 atom. 

The bond length is assumed to be 1.33 A by comparison with the molecules CFgX, and the bond angle is estimated from molecular-orbital calculations of Morokuma (1 ) and Pople and coworkers (13). The nonplanar structure is consistent with electron-spin-resonance spectra (j ) of CFg in krypton and xenon matrices, with infrared spectra of CFg in various matrices (15) and in the gaseous phase (j ), and with photolonlzatlon spectra (1 ). The principal moments of Inertia are I = Ig =... 

This standard had many advantages. For one thing, people worldwide could find the official length of a meter. All one needed was the equipment to heat a sample of krypton-86. Then one had to look for the reddish-orange line produced. The length of the meter, then, was 1,650,763.73 times the width of that line. 

Los Alamos Laboratory in New Mexico has terminated its work with the ANT ARES system operating at 10.6 micrometers because it was shown it would not be possible to generate sufficient heating or compression with the 10.6 micrometer wave length radiation. They have turned their efforts to the development of krypton-fluorine lasers. They have generated 10,000 joules pulses at 250 nanometers at efficiency of 1.5%. In 1989, this laser system had not yet been incorporated into a fusion test apparatus and little recent data is available. 

Crystallization of solutions of quinol [p-dihydroxybenzene, p-C6H4(OH)2] in water or alcohol under pressure of 10-40 atm of, say, krypton, produces crystals, often up to 1 cm in length, which are readily distinguishable from the crystals of ordinary quinol (a-quinol), even visually. These crystals contain the noble gas trapped in the lattice of -quinol. When the crystals are dissolved in water, or heated, the gas is released. The crystals are stable at room temperature and can be kept for years. 

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