STRONT

Wprowadzenie

Liczba atomowa: 38
Grupa: 2 or II A
Masa atomowa: 87.62
Okres: 5
Numer CAS: 7440-24-6

Klasyfikacja

tlenowce
Fluorowiec
Gaz szlachetny
lantanowców
Actinoid
Rare Earth Element
Platinum Grupa Metal
Transuran
Brak stabilnego Izotopy
Solidny
Ciekły
Gaz
Solidny (przewidywane)

Opis • Zastosowania / Funkcja

Isolated by Davey by electrolysis in 1808; however, Adair Crawford in 1790 recognized a new mineral (strontianite) as differing from other barium minerals (baryta).Strontium is found chiefly as celestite (SrSO4) and strontianite (SrCO3). The metal can be prepared by electrolysis of the fused chloride mixed withpotassium chloride, or is made by reducing strontium oxide with aluminum in a vacuum at a temperature at which strontium distills off. Three allotropicforms of the metal exist, with transition points at 235 and 540°C. Strontium is softer than calcium and decomposes water more vigorously. It does notabsorb nitrogen below 380°C. It should be kept under mineral oil to prevent oxidation. Freshly cut strontium has a silvery appearance, but rapidly turnsa yellowish color with the formation of the oxide. The finely divided metal ignites spontaneously in air. Volatile strontium salts impart a beautifulcrimson color to flames, and these salts are used in pyrotechnics and in the production of flares. Natural strontium is a mixture of four stable isotopes.Twenty six other unstable isotopes and isomers are known to exist. Of greatest importance is 90Sr with a half-life of 29 years. It is a product of nuclearfallout and presents a health problem. This isotope is one of the best long-lived high-energy beta emitters known, and is used in SNAP (Systems forNuclear Auxiliary Power) devices. These devices hold promise for use in space vehicles, remote weather stations, navigational buoys, etc., where alightweight, long-lived, nuclear-electric power source is needed. The major use for strontium at present is in producing glass for color television picturetubes. It has also found use in producing ferrite magnets and in refining zinc. Strontium titanate is an interesting optical material as it has an extremelyhigh refractive index and an optical dispersion greater than that of diamond. It has been used as a gemstone, but it is very soft. It does not occur naturally.Strontium metal (99% pure) costs about $1/g while the metal, 99.95% pure, sells for about $10/g. 1

• "used in fireworks and flares, which show the characteristic red glow of strontium in a flame." 2

Właściwości fizyczne

Temperatura topnienia:3*  777 °C = 1050.15 K = 1430.6 °F
Temperatura wrzenia:3* 1382 °C = 1655.15 K = 2519.6 °F
Punkt sublimacji:3 
Punkt potrójny:3 
Punkt krytyczny:3 
Gęstość:4  2.64 g/cm3

* - at 1 atm

Konfiguracja elektronów

Konfiguracja elektronów: [Kr] 5s2
Blok: s
Najwyższy poziom energii Zajęte: 5
Elektrony walencyjne: 2

Liczby kwantowe:

n = 5
ℓ = 0
m = 0
ms = -½

klejenie

elektroujemność (Paulinga):5 0.95
Electropositivity (Paulinga): 3.05
powinowactwo elektronowe:6 0.048 eV
utlenianie Zjednoczone: +2
Funkcja pracy:7 2.76 eV = 4.42152E-19 J

Potencjał jonizacyjny   eV 8  kJ/mol  
1 5.6949    549.5
2 11.03013    1064.2
3 42.89    4138.3
Potencjał jonizacyjny   eV 8  kJ/mol  
4 57    5499.7
5 71.6    6908.3
6 90.8    8760.9
7 106    10227.4
Potencjał jonizacyjny   eV 8  kJ/mol  
8 122.3    11800.2
9 162    15630.6
10 177    17077.9
11 324.1    31270.9

Termochemia

Ciepło właściwe: 0.301 J/g°C 9 = 26.374 J/mol°C = 0.072 cal/g°C = 6.303 cal/mol°C
Przewodność cieplna: 35.3 (W/m)/K, 27°C 10
Ciepło topnienia: 8.3 kJ/mol 11 = 94.7 J/g
Ciepło parowania: 144 kJ/mol 12 = 1643.5 J/g
Stan skupienia Entalpia formacji (ΔHf°)13 Entropia (S°)13 Gibbs Free Energy (ΔGf°)13
(kcal/mol) (kJ/mol) (cal/K) (J/K) (kcal/mol) (kJ/mol)
(s) 0 0 12.5 52.3 0 0
(ℓ) 1.82 7.61488 13.66 57.15344 1.47 6.15048
(g) 39.2 164.0128 39.32 164.51488 31.2 130.5408

izotopy

nuklidu Masa 14 Pół życia 14 spin jądrowy 14 Energia wiązania
100Sr 99.93535(14) 202(3) ms 0+ 837.95 MeV
101Sr 100.94052(13) 118(3) ms (5/2-) 841.36 MeV
102Sr 101.94302(12) 69(6) ms 0+ 849.43 MeV
103Sr 102.94895(54)# 50# ms [>300 ns] 857.51 MeV
104Sr 103.95233(75)# 30# ms [>300 ns] 0+ 856.26 MeV
105Sr 104.95858(75)# 20# ms [>300 ns] 864.33 MeV
73Sr 72.96597(64)# >25 ms 1/2-# 592.08 MeV
74Sr 73.95631(54)# 50# ms [>1.5 μs] 0+ 608.53 MeV
75Sr 74.94995(24) 88(3) ms (3/2-) 623.12 MeV
76Sr 75.94177(4) 7.89(7) s 0+ 638.65 MeV
77Sr 76.937945(10) 9.0(2) s 5/2+ 650.45 MeV
78Sr 77.932180(8) 159(8) s 0+ 663.17 MeV
79Sr 78.929708(9) 2.25(10) min 3/2(-) 674.04 MeV
80Sr 79.924521(7) 106.3(15) min 0+ 686.77 MeV
81Sr 80.923212(7) 22.3(4) min 1/2- 695.77 MeV
82Sr 81.918402(6) 25.36(3) d 0+ 708.50 MeV
83Sr 82.917557(11) 32.41(3) h 7/2+ 717.50 MeV
84Sr 83.913425(3) STABILNY 0+ 729.30 MeV
85Sr 84.912933(3) 64.853(8) d 9/2+ 738.30 MeV
86Sr 85.9092602(12) STABILNY 0+ 749.17 MeV
87Sr 86.9088771(12) STABILNY 9/2+ 758.17 MeV
88Sr 87.9056121(12) STABILNY 0+ 769.04 MeV
89Sr 88.9074507(12) 50.57(3) d 5/2+ 775.25 MeV
90Sr 89.907738(3) 28.90(3) a 0+ 783.32 MeV
91Sr 90.910203(5) 9.63(5) h 5/2+ 788.59 MeV
92Sr 91.911038(4) 2.66(4) h 0+ 795.73 MeV
93Sr 92.914026(8) 7.423(24) min 5/2+ 801.01 MeV
94Sr 93.915361(8) 75.3(2) s 0+ 808.15 MeV
95Sr 94.919359(8) 23.90(14) s 1/2+ 812.50 MeV
96Sr 95.921697(29) 1.07(1) s 0+ 818.70 MeV
97Sr 96.926153(21) 429(5) ms 1/2+ 822.12 MeV
98Sr 97.928453(28) 0.653(2) s 0+ 828.33 MeV
99Sr 98.93324(9) 0.269(1) s 3/2+ 831.74 MeV
Wartości oznaczone # nie jest całkowicie pochodzą z danych doświadczalnych, ale przynajmniej częściowo z systematycznej tendencji. Obraca się słabe argumenty przypisania są w nawiasach. 14

Obfitość

Ziemia - Związki źródłowe: carbonates/sulfates 15
Ziemia - Woda morska: 7.2 mg/L 16
Ziemia -  Skorupa:  370 mg/kg = 0.037% 16
Ziemia -  Całkowity:  14.5 ppm 17
Merkury) -  Całkowity:  1.11 ppm 17
Wenus -  Całkowity:  15.2 ppm 17
chondrytach - Całkowity: 20 (relative to 106 atoms of Si) 18
Ludzkie ciało - Całkowity: 0.00046% 19

związki

Informacje dotyczące bezpieczeństwa


Karta Charakterystyki - ACI Alloys, Inc.

Po więcej informacji

Linki zewnętrzne:

Czasopisma:
(1) Vaughan T. Bowen and T. T. Sugihara, Proc. Nat. Acad. Sci. U.S.A. 43, 576-580 (1957)
(2) Dasch, Hills and Turekian, Science 153, 295-297 (1966)
(3) A. R. Johnson, W. D. Armstrong and Leon Singer, Science 153, 1396-1397 (1966)

źródła

(1) - Lide, David R. CRC Handbook of Chemistry and Physics, 83rd ed.; CRC Press: Boca Raton, FL, 2002; p 4:29-4:30.
(2) - Whitten, Kenneth W., Davis, Raymond E., and Peck, M. Larry. General Chemistry 6th ed.; Saunders College Publishing: Orlando, FL, 2000; p 931.
(3) - Lide, David R. CRC Handbook of Chemistry and Physics, 83rd ed.; CRC Press: Boca Raton, FL, 2002; p 4:132.
(4) - Lide, David R. CRC Handbook of Chemistry and Physics, 84th ed.; CRC Press: Boca Raton, FL, 2002; p 4:39-4:96.
(5) - Dean, John A. Lange's Handbook of Chemistry, 11th ed.; McGraw-Hill Book Company: New York, NY, 1973; p 4:8-4:149.
(6) - Lide, David R. CRC Handbook of Chemistry and Physics, 84th ed.; CRC Press: Boca Raton, FL, 2002; p 10:147-10:148.
(7) - Speight, James. Lange's Handbook of Chemistry, 16th ed.; McGraw-Hill Professional: Boston, MA, 2004; p 1:132.
(8) - Lide, David R. CRC Handbook of Chemistry and Physics, 83rd ed.; CRC Press: Boca Raton, FL, 2002; p 10:178 - 10:180.
(9) - Lide, David R. CRC Handbook of Chemistry and Physics, 83rd ed.; CRC Press: Boca Raton, FL, 2002; p 4:133.
(10) - Lide, David R. CRC Handbook of Chemistry and Physics, 83rd ed.; CRC Press: Boca Raton, FL, 2002; pp 6:193, 12:219-220.
(11) - Lide, David R. CRC Handbook of Chemistry and Physics, 83rd ed.; CRC Press: Boca Raton, FL, 2002; pp 6:123-6:137.
(12) - Lide, David R. CRC Handbook of Chemistry and Physics, 83rd ed.; CRC Press: Boca Raton, FL, 2002; pp 6:107-6:122.
(13) - Dean, John A. Lange's Handbook of Chemistry, 12th ed.; McGraw-Hill Book Company: New York, NY, 1979; p 9:4-9:94.
(14) - Atomic Mass Data Center. http://amdc.in2p3.fr/web/nubase_en.html (accessed July 14, 2009).
(15) - Silberberg, Martin S. Chemistry: The Molecular Nature of Matter and Change, 4th ed.; McGraw-Hill Higher Education: Boston, MA, 2006, p 965.
(16) - Lide, David R. CRC Handbook of Chemistry and Physics, 83rd ed.; CRC Press: Boca Raton, FL, 2002; p 14:17.
(17) - Morgan, John W. and Anders, Edward, Proc. Natl. Acad. Sci. USA 77, 6973-6977 (1980)
(18) - Brownlow, Arthur. Geochemistry; Prentice-Hall, Inc.: Englewood Cliffs, NJ, 1979, pp 15-16.
(19) - Lide, David R. CRC Handbook of Chemistry and Physics, 83rd ed.; CRC Press: Boca Raton, FL, 2002; p 7:17.