Search results
Results From The WOW.Com Content Network
Radioactive krypton-81 is the product of spallation reactions with cosmic rays striking gases present in the Earth atmosphere, along with the six stable or nearly stable krypton isotopes. [11] Krypton-81 has a half-life of about 229,000 years. Krypton-81 is used for dating ancient (50,000- to 800,000-year-old) groundwater and to determine their ...
In 1960, the International Bureau of Weights and Measures defined the meter as 1,650,763.73 wavelengths of light emitted in the vacuum corresponding to the transition between the 2p 10 and 5d 5 levels in the isotope krypton-86. [14] [15] This agreement replaced the 1889 international prototype meter, which was a metal bar located in Sèvres.
Template: Infobox krypton isotopes. 2 languages. Simple English; ... 86 Kr 17.3% stable Standard atomic weight A r °(Kr) 83.798 ...
This is a list of radioactive nuclides (sometimes also called isotopes), ordered by half-life from shortest to longest, in seconds, minutes, hours, days and years. Current methods make it difficult to measure half-lives between approximately 10 −19 and 10 −10 seconds.
Of the 26 "monoisotopic" elements that have only a single stable isotope, all but one have an odd atomic number—the single exception being beryllium. In addition, no odd-numbered element has more than two stable isotopes, while every even-numbered element with stable isotopes, except for helium, beryllium, and carbon, has at least three.
Isotopes of krypton. Main isotopes [10] Decay; abundance half-life (t 1/2) mode ... 86 Kr 17.3% stable Data sets read by {{Infobox element}} Name and identifiers
The krypton-86 discharge lamp operating at the triple point of nitrogen (63.14 K, −210.01 °C) was the state-of-the-art light source for interferometry in 1960, but it was soon to be superseded by a new invention: the laser, of which the first working version was constructed in the same year as the redefinition of the metre. [178]
Se-79, half-life of 327k years, is one of the long-lived fission products.Given the stability of its next lighter and heavier isotopes and the high cross section those isotopes exhibit for various neutron reactions, it is likely that the relatively low yield is due to Se-79 being destroyed in the reactor to an appreciable extent.