CRIPTÓN

Introducción

Número atómico: 36
Grupo: 18 or VIII A
Peso atomico: 83.798
Período: 4
Número CAS: 7439-90-9

Clasificación

chalcogen
halógeno
Gas noble
Lantanoides
Actinoides
Elemento de tierras raras
Platino Metal Group
transuranium
No hay isótopos estables
Sólido
Líquido
Gas
Sólido (Predicho)

Descripción • Usos / Función

Discovered in 1898 by Ramsay and Travers in the residue left after liquid air had nearly boiled away. Krypton is present in the air to the extent of about 1 ppm. The atmosphere of Mars has been found to contain 0.3 ppm of krypton. It is one of the “noble” gases. It is characterized by its brilliant green and orange spectral lines. Naturally occurring krypton contains six stable isotopes. Twenty four other unstable isotopes and isomers are now recognized. The spectral lines of krypton are easily produced and some are very sharp. In 1960 it was internationally agreed that the fundamental unit of length, the meter, should be defined in terms of the orange-red spectral line of 86Kr. This replaced the standard meter of Paris, which was defined in terms of a bar made of a platinum-iridium alloy. In October 1983 the meter, which originally was defined as being one ten millionth of a quadrant of the earth’s polar circumference, was again redefined by the International Bureau of Weights and Measures as being the length of path traveled by light in a vacuum during a time interval of 1/299,792,458 of a second. Solid krypton is a white crystalline substance with a face-centered cubic structure which is common to all the “rare gases”. While krypton is generally thought of as a rare gas that normally does not combine with other elements to form compounds, it now appears that the existence of some krypton compounds is established. Krypton difluoride has been prepared in gram quantities and can be made by several methods. A higher fluoride of krypton and a salt of an oxyacid of krypton also have been reported. Molecule-ions of ArKr+ and KrH+ have been identified and investigated, and evidence is provided for the formation of KrXe or KrXe+. Krypton clathrates have been prepared with hydroquinone and phenol. 85Kr has found recent application in chemical analysis. By imbedding the isotope in various solids, kryptonates are formed. The activity of these kryptonates is sensitive to chemical reactions at the surface. Estimates of the concentration of reactants are therefore made possible. Krypton is used in certain photographic flash lamps for high-speed photography. Uses thus far have been limited because of its high cost. Krypton gas presently costs about $690/100 L. 1

• "Krypton and xenon are likewise used, but to a much smaller extent, in the filling of fluorescent lamps and other special lamps." 2
• "Airport runway and approach lights" 3

Propiedades físicas

Punto de fusion:4
Punto de ebullición:4* -153.22 °C = 119.93 K = -243.796 °F
Punto de sublimación:4 
Triple punto:4 -157.38 °C = 115.77 K = -251.284 °F at 73.2 kPa
Punto crítico:4 -63.74 °C = 209.41 K = -82.732 °F 4
Densidad:5  3.425 g/L

* - at 1 atm

Configuración electronica

Configuración electronica: [Ar] 4s2 3d10 4p6
Bloquear: p
Ocupado más alto nivel de energía: 4
Electrones de valencia: 8

Números cuánticos:

n = 4
ℓ = 1
m = 1
ms = -½

Vinculación

Afinidad electronica:6 not stable eV
estados de oxidación: 0

potencial de ionización   eV 7  kJ/mol  
1 13.99961    1350.8
2 24.35985    2350.4
3 36.95    3565.1
4 52.5    5065.5
5 64.7    6242.6
6 78.5    7574.1
7 111    10709.9
8 125.802    12138.0
9 230.85    22273.6
10 268.2    25877.4
potencial de ionización   eV 7  kJ/mol  
11 308    29717.5
12 350    33769.9
13 391    37725.8
14 447    43128.9
15 492    47470.8
16 541    52198.6
17 592    57119.3
18 641    61847.1
19 786    75837.5
20 833    80372.3
potencial de ionización   eV 7  kJ/mol  
21 884    85293.0
22 937    90406.7
23 998    96292.3
24 1051    101406.1
25 1151    111054.6
26 1205.3    116293.7
27 2928    282509.0
28 3070    296209.9
29 3227    311358.1
30 3381    326216.8

termoquímica

Calor especifico: 0.248 J/g°C 8 = 20.782 J/mol°C = 0.059 cal/g°C = 4.967 cal/mol°C
Conductividad térmica: 0.00949 (W/m)/K, 27°C 9
Calor de fusión: 1.638 kJ/mol 10 = 19.5 J/g
Calor de vaporización: 9.029 kJ/mol 11 = 107.7 J/g
Estado de la materia Entalpía de formación (ΔHf°)12 entropía (S°)12 Energía libre de Gibbs (ΔGf°)12
(kcal/mol) (kJ/mol) (cal/K) (J/K) (kcal/mol) (kJ/mol)
(g) 0 0 39.191 163.975144 0 0

isótopos

nucleido Masa 13 Media vida 13 spin nuclear 13 Energía de unión
100Kr 99.96114(54)# 10# ms [>300 ns] 0+ 815.29 MeV
69Kr 68.96518(43)# 32(10) ms 5/2-# 561.36 MeV
70Kr 69.95526(41)# 52(17) ms 0+ 578.74 MeV
71Kr 70.94963(70) 100(3) ms (5/2)- 592.40 MeV
72Kr 71.942092(9) 17.16(18) s 0+ 607.00 MeV
73Kr 72.939289(7) 28.6(6) s 3/2- 617.86 MeV
74Kr 73.9330844(22) 11.50(11) min 0+ 631.52 MeV
75Kr 74.930946(9) 4.29(17) min 5/2+ 642.39 MeV
76Kr 75.925910(4) 14.8(1) h 0+ 655.12 MeV
77Kr 76.9246700(21) 74.4(6) min 5/2+ 664.12 MeV
78Kr 77.9203648(12) ESTABLE 0+ 675.92 MeV
79Kr 78.920082(4) 35.04(10) h 1/2- 683.99 MeV
80Kr 79.9163790(16) ESTABLE 0+ 695.79 MeV
81Kr 80.9165920(21) 2.29(11)E+5 a 7/2+ 703.86 MeV
82Kr 81.9134836(19) ESTABLE 0+ 714.72 MeV
83Kr 82.914136(3) ESTABLE 9/2+ 721.86 MeV
84Kr 83.911507(3) ESTABLE 0+ 732.73 MeV
85Kr 84.9125273(21) 10.776(3) a 9/2+ 739.87 MeV
86Kr 85.91061073(11) ESTABLE 0+ 749.80 MeV
87Kr 86.91335486(29) 76.3(5) min 5/2+ 755.08 MeV
88Kr 87.914447(14) 2.84(3) h 0+ 762.22 MeV
89Kr 88.91763(6) 3.15(4) min 3/2(+#) 767.50 MeV
90Kr 89.919517(20) 32.32(9) s 0+ 773.70 MeV
91Kr 90.92345(6) 8.57(4) s 5/2(+) 778.05 MeV
92Kr 91.926156(13) 1.840(8) s 0+ 783.33 MeV
93Kr 92.93127(11) 1.286(10) s 1/2+ 786.74 MeV
94Kr 93.93436(32)# 210(4) ms 0+ 792.02 MeV
95Kr 94.93984(43)# 114(3) ms 1/2(+) 795.43 MeV
96Kr 95.94307(54)# 80(7) ms 0+ 799.78 MeV
97Kr 96.94856(54)# 63(4) ms 3/2+# 803.19 MeV
98Kr 97.95191(64)# 46(8) ms 0+ 808.47 MeV
99Kr 98.95760(64)# 40(11) ms (3/2+)# 810.95 MeV
Los valores marcados con # no son puramente derivan de los datos experimentales, pero al menos en parte, de las tendencias sistemáticas. Hace girar con débiles argumentos de asignación se incluyen entre paréntesis. 13

Abundancia

Tierra - Los compuestos de origen: uncombined 14
Tierra - Agua de mar: 0.00021 mg/L 15
Tierra -  Corteza:  0.0001 mg/kg = 0.00000001% 15
Tierra -  Total:  0.0236E-8 cm^3/g 16
Planeta mercurio) -  Total:  16
Venus -  Total:  2.30E-8 cm^3/g 16

Compuestos

Información de seguridad


Ficha de datos de seguridad de materiales - ACI Alloys, Inc.

Para más información

Enlaces externos:

Fuentes

(1) - Lide, David R. CRC Handbook of Chemistry and Physics, 83rd ed.; CRC Press: Boca Raton, FL, 2002; p 4:17.
(2) - Jolly, William L. The Chemistry of the Non-Metals; Prentice-Hall: Englewood Cliffs, New Jersey, 1966; p 23.
(3) - Whitten, Kenneth W., Davis, Raymond E., and Peck, M. Larry. General Chemistry 6th ed.; Saunders College Publishing: Orlando, FL, 2000; p 944.
(4) - Lide, David R. CRC Handbook of Chemistry and Physics, 83rd ed.; CRC Press: Boca Raton, FL, 2002; p 4:132.
(5) - Lide, David R. CRC Handbook of Chemistry and Physics, 84th ed.; CRC Press: Boca Raton, FL, 2002; p 4:39-4:96.
(6) - Lide, David R. CRC Handbook of Chemistry and Physics, 84th ed.; CRC Press: Boca Raton, FL, 2002; p 10:147-10:148.
(7) - Lide, David R. CRC Handbook of Chemistry and Physics, 83rd ed.; CRC Press: Boca Raton, FL, 2002; p 10:178 - 10:180.
(8) - Lide, David R. CRC Handbook of Chemistry and Physics, 83rd ed.; CRC Press: Boca Raton, FL, 2002; p 4:133.
(9) - Lide, David R. CRC Handbook of Chemistry and Physics, 83rd ed.; CRC Press: Boca Raton, FL, 2002; pp 6:193, 12:219-220.
(10) - Lide, David R. CRC Handbook of Chemistry and Physics, 83rd ed.; CRC Press: Boca Raton, FL, 2002; pp 6:123-6:137.
(11) - Lide, David R. CRC Handbook of Chemistry and Physics, 83rd ed.; CRC Press: Boca Raton, FL, 2002; pp 6:107-6:122.
(12) - Dean, John A. Lange's Handbook of Chemistry, 12th ed.; McGraw-Hill Book Company: New York, NY, 1979; p 9:4-9:94.
(13) - Atomic Mass Data Center. http://amdc.in2p3.fr/web/nubase_en.html (accessed July 14, 2009).
(14) - Silberberg, Martin S. Chemistry: The Molecular Nature of Matter and Change, 4th ed.; McGraw-Hill Higher Education: Boston, MA, 2006, p 965.
(15) - Lide, David R. CRC Handbook of Chemistry and Physics, 83rd ed.; CRC Press: Boca Raton, FL, 2002; p 14:17.
(16) - Morgan, John W. and Anders, Edward, Proc. Natl. Acad. Sci. USA 77, 6973-6977 (1980)