Krypton (Kr) is located in group 18, and in period 4. (http://www.rsc.org/periodic-table/element/36/krypton)
Krypton was discovered on May 30, 1898 by Sir William Ramsay, a Scottish chemist, and Morris M. Travers, an English chemist, while studying liquefied air. Small amounts of liquid krypton remained behind after the more volatile components of liquid air had boiled away (http://education.jlab.org/itselemental/ele036.html)
The name "Krypton" is derived from the Greek "kryptos", meaning hidden
Krypton is present in the atmosphere in extremely minute quantities (about 1 part per million) and is produced commercially as a byproduct in the preparation of liquid air. (http://www.chemeddl.org/resources/ptl/)
Atomic mass - 83.80
Atomic Number - 36
Number of Protons - 36
Number of neutrons - 84-36 = 48
Number of Electrons - 36
Krypton has 37 known isotopes (not all are stable)
(http://periodic.lanl.gov/36.shtml)
There are six stable isotopes of krypton that occur in nature (shown above). (http://www.softschools.com/facts/periodic_table/krypton_facts/214/)
The abundance of krypton in the atmosphere is thought to be about 0.000108 to 0.000114 percent. The element is also formed in the Earth's crust when uranium and other radioactive elements break down. The amount in the Earth's crust is too small to estimate, however. (http://www.encyclopedia.com/science-and-technology/chemistry/compounds-and-elements/krypton)
Krypton is used in some types of photographic flashes used in high speed photography. Some fluorescent light bulbs are filled with a mixture of krypton and argon gases. Krypton gas is also combined with other gases to make luminous signs that glow with a greenish-yellow light. (http://education.jlab.org/itselemental/ele036.html)
Krypton fluoride is used in some high powered lasers. (http://www.rsc.org/periodic-table/element/36/krypton)
Between 1960 and 1983, an international agreement defined the meter length in terms of the wavelength of light emitted from the krypton isotope, 86Kr. (http://www.chemicool.com/elements/krypton.html)
When electric current is passed through krypton gas, it gives off a very bright light. A common occurrence of this is in airport runway lights, which are very bright so pilots can see them from far away in foggy or bad weather conditions. (http://www.encyclopedia.com/science-and-technology/chemistry/compounds-and-elements/krypton)
Krypton-fluoride lasers produce pulses with 500 times the power of the entire U.S. electrical grid. Not surprisingly, these pulses are of short duration: four billionths of a second (http://www.chemicool.com/elements/krypton.html)
Krypton-85 in the atmosphere can be used to detect the presence of otherwise secret nuclear weapons research and production facilities. (http://www.softschools.com/facts/periodic_table/krypton_facts/214/)
Krypton-83 has medical uses in MRI technology. (http://www.softschools.com/facts/periodic_table/krypton_facts/214/)
Krypton's wavelength is 605.78 nanometers long. (http://www.softschools.com/facts/periodic_table/krypton_facts/214/)
Krypton's Story - THE END