NÉON

Introdução

Número atômico: 10
Grupo: 18 or VIII A
Peso atômico: 20.1797
Período: 2
Número CAS: 7440-01-9

Classificação

Calcogênio
halogênio
Gás nobre
Lantanóides
Actinóide
Terra-rara
Platinum Metal Group
Transuranium
Não Isótopos Estáveis
Sólido
Líquido
Gás
Sólido (previsto)

Descrição • Usos / Função

Discovered by Ramsay and Travers in 1898. Neon is a rare gaseous element present in the atmosphereto the extent of 1 part in 65,000 of air. It is obtained by liquefaction of air and separated from the other gases by fractional distillation. Natural neonis a mixture of three isotopes. Six other unstable isotopes are known. It is very inert element; however, it is said to form a compound with fluorine.It is still questionable if true compounds of neon exist, but evidence is mounting in favor of their existence. The following ions are known from opticaland mass spectrometric studies: Ne+, (NeAr)+, (NeH)+, and (HeNe+). Neon also forms an unstable hydrate. In a vacuum discharge tube, neon glowsreddish orange. Of all the rare gases, the discharge of neon is the most intense at ordinary voltages and currents. Neon is used in making the commonneon advertising signs, which accounts for its largest use. It is also used to make high-voltage indicators, lightning arrestors, wave meter tubes, andTV tubes. Neon and helium are used in making gas lasers. Liquid neon is now commercially available and is finding important application as aneconomical cryogenic refrigerant. It has over 40 times more refrigerating capacity per unit volume than liquid helium and more than three times thatof liquid hydrogen. It is compact, inert, and is less expensive than helium when it meets refrigeration requirements. Neon costs about $800/80 cu. ft.(2265 L). 1

• "Neon signs" 2
• "The French chemist Georges Claude (1870-1960) worked with neon vapor lamps; beginning in 1927, he was able to produce them in quantity. Vapor lamps containing a variety of different gases of gas mixtures could be bent into attractive shapes, or into letters that spelled out words (and usually carried an advertising message). So prominent was the red color of those vapor lamps containing neon that all of them, whether they actually contained neon or not, came to be called neon lights.

A small, dim version of the neon light is the neon glow lamp, which consists of a small bulb containing electrodes in a neon atmosphere. Electricity is forced through the neon, causing it to produce a red glow. Little electricity is required for the purpose, and the lamp is not really intended for illumination, but merely as a signal - to indicate the location of a switch or to act as evidence that some electric circuit is in working order (or, perhaps, is not in working order).

In 1957, the spark chamber was introduced for the detection of subatomic particles, and proved to be more efficient for many purposes than the older detection devices. The spark chamber consists of closely spaced metal plates, with alternate plates highly charged with electricity, so that an electric spark is at the point of being released. When a subatomic particle speeds through, sparks are released at the points where it strikes the plates. Between the plates of this device an inert gas is used, either neon or argon.

Efforts were made at once to produce continuous lasers, and the ruby was replaced by tubes of gas. The gas lasers so produced, later in 1960, were continuous. The gases used in such lasers include all of the stable noble gases, alone or in combination. The first gas laser, produced by the Iranian physicist Ali Javan (b. 1926), working at Bell Telephone Laboratories, made use of a mixture of neon and helium. This variety is still the most important." 3

Propriedades físicas

Ponto de fusão:4*  -248.59 °C = 24.56 K = -415.462 °F
Ponto de ebulição:4* -246.08 °C = 27.07 K = -410.944 °F
Ponto de sublimação:4 
Ponto Triplo:4 
Ponto crítico:4 -228.7 °C = 44.45 K = -379.66 °F 4
Densidade:5  0.825 g/L

* - at 1 atm

Configuração Electron

Configuração Electron: [He] 2s2 2p6
Quadra: p
Mais alto nível de energia Ocupado: 2
Elétrons de valência: 8

Números quânticos:

n = 2
ℓ = 1
m = 1
ms = -½

Colagem

Electron Affinity:6 not stable eV
oxidação Unidos: 0

potencial de ionização   eV 7  kJ/mol  
1 21.5646    2080.7
2 40.96328    3952.4
3 63.45    6122.0
potencial de ionização   eV 7  kJ/mol  
4 97.12    9370.7
5 126.21    12177.4
6 157.93    15237.9
potencial de ionização   eV 7  kJ/mol  
7 207.2759    19999.1
8 239.0989    23069.5
9 1195.8286    115379.9
10 1362.1995    131432.2

Termoquímica

Calor específico: 1.030 J/g°C 8 = 20.785 J/mol°C = 0.246 cal/g°C = 4.968 cal/mol°C
Condutividade térmica: 0.0493 (W/m)/K, 27°C 9
Calor de fusão: 0.3317 kJ/mol 10 = 16.4 J/g
Calor da vaporização: 1.7326 kJ/mol 11 = 85.9 J/g
Estado da matéria Entalpia de formação (ΔHf°)12 entropia (S°)12 Gibbs Energia Livre (ΔGf°)12
(kcal/mol) (kJ/mol) (cal/K) (J/K) (kcal/mol) (kJ/mol)
(g) 0 0 34.95 146.2308 0 0

isótopos

nuclide Massa 13 Meia vida 13 spin nuclear 13 Energia de ligação
16Ne 16.025761(22) 9E-21 s [122(37) keV] 0+ 98.03 MeV
17Ne 17.017672(29) 109.2(6) ms 1/2- 113.55 MeV
18Ne 18.0057082(3) 1.672(8) s 0+ 132.80 MeV
19Ne 19.0018802(3) 17.296(5) s 1/2+ 144.60 MeV
20Ne 19.9924401754(19) ESTÁVEL 0+ 161.05 MeV
21Ne 20.99384668(4) ESTÁVEL 3/2+ 168.19 MeV
22Ne 21.991385114(19) ESTÁVEL 0+ 178.13 MeV
23Ne 22.99446690(11) 37.24(12) s 5/2+ 183.41 MeV
24Ne 23.9936108(4) 3.38(2) min 0+ 192.41 MeV
25Ne 24.997737(28) 602(8) ms (3/2)+ 196.75 MeV
26Ne 26.000461(29) 197(1) ms 0+ 202.03 MeV
27Ne 27.00759(12) 32(2) ms (3/2+)# 203.58 MeV
28Ne 28.01207(16) 18.3(22) ms 0+ 207.00 MeV
29Ne 29.01939(29) 15.6(5) ms (3/2+)# 208.55 MeV
30Ne 30.02480(61) 5.8(2) ms 0+ 211.96 MeV
31Ne 31.03311(97)# 3.4(8) ms 7/2-# 211.65 MeV
32Ne 32.04002(86)# 3.5(9) ms 0+ 213.20 MeV
33Ne 33.04938(86)# <260 ns 7/2-# 212.89 MeV
34Ne 34.05703(87)# 1# ms [>1.5 μs] 0+ 213.51 MeV
Os valores marcados # não são puramente derivado a partir de dados experimentais, mas, pelo menos, parcialmente a partir de tendências sistemáticas. Gira com argumentos de atribuição fracos estão entre parênteses. 13

Abundância

Terra - Os compostos de origem: uncombined 14
Terra - A água do mar: 0.00012 mg/L 15
Terra -  crosta:  0.005 mg/kg = 0.0000005% 15
Terra -  Total:  0.50E-8 cm^3/g 16
Planeta Mercúrio) -  Total:  16
Vênus -  Total:  49E-8 cm^3/g 16
condritos - Total: 0.0015 (relative to 106 atoms of Si) 17

Informação de Segurança


Material Safety Data Sheet - ACI Alloys, Inc.

Para maiores informações

Links externos:

Fontes

(1) - Lide, David R. CRC Handbook of Chemistry and Physics, 83rd ed.; CRC Press: Boca Raton, FL, 2002; p 4:20.
(2) - Whitten, Kenneth W., Davis, Raymond E., and Peck, M. Larry. General Chemistry 6th ed.; Saunders College Publishing: Orlando, FL, 2000; p 944.
(3) - Asimov, Isaac. The Noble Gases; Basic Books, Inc.: New York City, 1966; pp 86-88.
(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)
(17) - Brownlow, Arthur. Geochemistry; Prentice-Hall, Inc.: Englewood Cliffs, NJ, 1979, pp 15-16.