Xenon

Xenon
The location of xenon
Symbol	Xe
Number	54
Group, Period	18, 5
Electrons per shell	2, 8, 18, 18, 8
Discoverer	"Sir" William Ramsay, and Morris Travers
Date discovered	July 12, 1898
Location discovered	England
Atomic Weight	131.293
Category	Noble Gas

Xenon is an element with the symbol Xe. The atomic number of this element is 54. As a colourless, odourless noble gas, xenon is in the earth's atmosphere in small amounts. Xenon, generally unreactive, can undergo some chemical reactions, such as xenon hexafluoroplatinate, the first noble gas compound synthesized. Xenon is quite rare at 1 in 1 million in the Earth's atmosphere.

There are nine stable isotopes, second only to tin, and over 40 unstable isotopes of xenon.

Xenon is commonly used in flash lamps, and arc lamps, and a general anesthetic.

History

This element was discovered in England by Sir William Ramsay and Morris Travers in 1898, shortly after the discoveries of krypton and neon. The two found it in residue from evaporating air.

Naming

Ramsay suggested to name the element xenon, from the Greek word ξένον meaning foreigner, stanger, or guest.

Inventions and discoveries

In the 1930s, Harold Edgerton explored strobe light technology, for high-speed photography. This led to the invention of the xenon flash lamp.

In 1939, Albert R. Behnke Jr. started exploring "drunkenness" in divers. He tested the effects by varying the breathing mixes on his subjects and discovered that this caused divers to perceive change in depth. He then created an anesthetic with this gas.

Xenon flash

In 1960, John Reynolds discovered that certain meteorites had contained isotopic anomaly with an overabundance of xenon-129. ¹²⁹Xe forms by beta decay of ¹²⁹I, which has a 15 million year half-life. This was early evidence that a supernova had triggered formation of the solar system.

Flashtubes with xenon were also created in the 21st century.

Occurrence and production

Xenon is a trace gas in Earth's atmosphere, with only 0.087±0.001 parts per million, and is also found in some gases created through mineral springs. Some radioactive isotopes of xenon, such as ¹³³Xe, and ¹³⁵Xe are created through neutron irradiation of fissionable material in nuclear reactors.

Xenon is also obtained commercially through separation of air.

Nuclear Properties

Wikipedia's article "Isotopes of Xenon" provides a thorough description of observed Xe isotopes and their isomers.

Xenon is stabilized by the neutron shell closure at N = 82, which accounts for its large number of stable isotopes (second only to tin). On the other hand, its longest-lived radioisotope is ¹²⁷Xe at 36.4 days.

To judge from abundances, both slow neutron capture during the late evolution of low-mass stars or rapid neutron capture (r process) occurring during supernovae or neutron star mergers (kilonovae) can produce Xe. Its two heaviest isotopes, ¹³⁴Xe and ¹³⁶Xe, can only form by the r process. Its two lightest isotopes are also formed in supernovae by reactions in which capturing a gamma ray photon causes a nucleus to eject a neutron, Since a kilonova cools more quickly, it is less likely to produce the lightest Xe isotopes.

9-Period Periodic Table of Elements
1	1 H																																																																	2 He
2	3 Li	4 Be																																																																	5 B	6 C	7 N	8 O	9 F	10 Ne
3	11 Na	12 Mg																																																																	13 Al	14 Si	15 P	16 S	17 Cl	18 Ar
4	19 K	20 Ca																																																																	21 Sc	22 Ti	23 V	24 Cr	25 Mn	26 Fe	27 Co	28 Ni	29 Cu	30 Zn	31 Ga	32 Ge	33 As	34 Se	35 Br	36 Kr
5	37 Rb	38 Sr																																																																	39 Y	40 Zr	41 Nb	42 Mo	43 Tc	44 Ru	45 Rh	46 Pd	47 Ag	48 Cd	49 In	50 Sn	51 Sb	52 Te	53 I	54 Xe
6	55 Cs	56 Ba																																																					57 La	58 Ce	59 Pr	60 Nd	61 Pm	62 Sm	63 Eu	64 Gd	65 Tb	66 Dy	67 Ho	68 Er	69 Tm	70 Yb	71 Lu	72 Hf	73 Ta	74 W	75 Re	76 Os	77 Ir	78 Pt	79 Au	80 Hg	81 Tl	82 Pb	83 Bi	84 Po	85 At	86 Rn
7	87 Fr	88 Ra																																																					89 Ac	90 Th	91 Pa	92 U	93 Np	94 Pu	95 Am	96 Cm	97 Bk	98 Cf	99 Es	100 Fm	101 Md	102 No	103 Lr	104 Rf	105 Db	106 Sg	107 Bh	108 Hs	109 Mt	110 Ds	111 Rg	112 Cn	113 Nh	114 Fl	115 Mc	116 Lv	117 Ts	118 Og
8	119 Uue	120 Ubn																															121 Ubu	122 Ubb	123 Ubt	124 Ubq	125 Ubp	126 Ubh	127 Ubs	128 Ubo	129 Ube	130 Utn	131 Utu	132 Utb	133 Utt	134 Utq	135 Utp	136 Uth	137 Uts	138 Uto	139 Ute	140 Uqn	141 Uqu	142 Uqb	143 Uqt	144 Uqq	145 Uqp	146 Uqh	147 Uqs	148 Uqo	149 Uqe	150 Upn	151 Upu	152 Upb	153 Upt	154 Upq	155 Upp	156 Uph	157 Ups	158 Upo	159 Upe	160 Uhn	161 Uhu	162 Uhb	163 Uht	164 Uhq	165 Uhp	166 Uhh	167 Uhs	168 Uho	169 Uhe	170 Usn	171 Usu	172 Usb
9	173 Ust	174 Usq
Alkali metal Alkaline earth metal Lanthanide Actinide Superactinide Transition metal Post-transition metal Metalloid Other nonmetal Halogen Noble gas predicted predicted predicted predicted predicted predicted predicted predicted predicted