РефератыИностранный языкKRKRYPTON Essay Research Paper I am the

KRYPTON Essay Research Paper I am the

KRYPTON Essay, Research Paper


I am the chemical element known as Krypton. I


can also be referred as Kr. I will be telling you


about my history, my properties, my family and my


occurrence. I will also be telling you about my


uses and ores, also the analytical methods based


on me.


I received the name krypton from the Greek word


"hidden" because I was hiding for so long,


undetected. I am from a rare group of gases called


noble gases. The other noble gases are helium,


xenon, neon, argon and radon. I was discovered


in England in 1898 almost 100 years ago by Sir


William Ramsey and Morris W. Travers. They


found me in the less volatile part of inert-gas


mixture left after oxygen had been chemically


removed from a sample of air. I am about one


millionth of the earth’s atmosphere. Only about 2 x


10-8% of the weight of the earth am I. I am a


colorless, odorless and tasteless gas. My atomic


number is 36. My atomic weight is 83.80. My


melting point is -157.20°C or -251.5°F. My gas


density at 0°C is 3.749 g/liter. My valence is 0,2.


Many of my physical properties differ according to


various scientists. The outer shell of my atom is


filled with electrons in a stable structure. That is


why there is only one atom in my element. No one


yet has prepared a chemical compound for me


that is stable at room temperature. I can be


trapped in crystals of different host compounds to


form a clathrate. The radioactive isotopes of me


known to this point are 76Kr, 77Kr, 79Kr, 81Kr,


83Kr, 85Kr, 87Kr-95Kr and 97Kr. My isotopes are


produced as by-products of nuclear fission of

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uranium in nuclear reactors. They can also be


formed in particle accelerator such as the


cyclotron. Until 1962, I, like other members of my


noble gas family, was thought to be chemically


inert. Even now the only well known


characteristics of my compound are diflouride,


KrF2, and its complexes. The diflouride can be


prepared by passing an electric discharge through


a 1:1 mixture of gaseous fluorine and me at -188°


C. After the reaction is complete, the reactor will


be warmed and put into a glass vessel. I arise in


the earth’s soil, through the breakdown of uranium,


but not the radioactive breakdown though. That


may be why I am very similar to another noble


gas, Xenon. Also, the mixture of stable and


radioactive isotopes of me are produced in nuclear


reactors by the slow neutron fission of uranium.


The only stable source for me is air. The content


of my gases can be detected and determined by


gas chromatography. Before scientists had these


methods of determining my content, they obtained


it by passing a gas sample through an electric


discharge tube at low pressures and analyzing the


light with a spectrometer. The principle and most


common use for me in the world is in filling electric


lamps and electronic devices of various types. I


am used to fill greenish fluorescent lights. Both


Argon and I can be used to fill lamps with light.


My radioactive 85 is used in leak testing of sealed


containers. Another use for me is continuous


measurements, determining thickness of materials,


such as paper. I hope you have learned a little bit


more about such a small element like me.

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