AKTINIUM

Einführung

Ordnungszahl: 89
Gruppe: 3 or III B
Atomares Gewicht: 227
Periode: 7
CAS-Nummer: 7440-34-8

Einstufung

Metall
Nonmetal
metalloider
Alkalimetall
Erdalkalimetalls
Übergangsmetall
Chalkogenhaltige
Halogen
Edelgas
Lanthanoid
Actinoidenelemente
Seltene Erden
Platingruppenmetall
Transurane
Keine Stabile Isotope
Solide
Flüssigkeit
Gas
Solide (Prognostizierte)

Beschreibung • Verwendung / Funktion

Discovered by Andre Debierne in 1899 and independently by F. Giesel in 1902. Occurs naturally in association with uranium minerals. Thirty two isotopes and isomers are now recognized. All are radioactive. Actinium-227, a decay product of uranium-235, is an alpha and beta emitter with a 21.77-year halflife. Its principal decay products are thorium-227 (18.72-day half-life), radium-223 (11.4-day half-life), and a number of short-lived products including radon, bismuth, polonium, and lead isotopes. In equilibrium with its decay products, it is a powerful source of alpha rays. Actinium metal has been prepared by the reduction of actinium fluoride with lithium vapor at about 1100 to 1300°C. The chemical behavior of actinium is similar to that of the rare earths, particularly lanthanum. Purified actinium comes into equilibrium with its decay products at the end of 185 days, and then decays according to its 21.77-year half-life. It is about 150 times as active as radium, making it of value in the production of neutrons. 1

Physikalische Eigenschaften

Schmelzpunkt:2*  1051 °C = 1324.15 K = 1923.8 °F
Siedepunkt:2* 3198 °C = 3471.15 K = 5788.4 °F
Sublimationspunkt:2 
Dreifacher Punkt:2 
Kritischer Punkt:2 
Dichte:3  10 g/cm3

* - at 1 atm

Elektronenkonfiguration

Elektronenkonfiguration:  *[Rn] 7s2 5f1
Block: d
Höchster besetztes Energieniveau: 7
Valenzelektronen: 

Quantenzahlen:

n = 5
ℓ = 3
m = -3
ms = +½

Kleben

Elektronegativität (Pauling-Skala):4 1.1
Electropositivity (Pauling-Skala): 2.9
Elektronenaffinität:5 0.35 eV
oxidations~~POS=TRUNC: +3

Ionisationspotential   eV 6  kJ/mol  
Ionisationspotential   eV 6  kJ/mol  
1 5.17    498.8
Ionisationspotential   eV 6  kJ/mol  
2 12.1    1167.5

Thermochemie

Spezifische Wärme: 0.120 J/g°C 7 = 27.240 J/mol°C = 0.029 cal/g°C = 6.511 cal/mol°C
Wärmeleitfähigkeit: 12 (W/m)/K, 27°C 8
Schmelzwärme: 
Verdampfungswärme: 
Aggregatszustand Bildungsenthalpie (ΔHf°)9 Entropie (S°)9 Gibbs-Energie (ΔGf°)9
(kcal/mol) (kJ/mol) (cal/K) (J/K) (kcal/mol) (kJ/mol)
(s) 0 0 15.00 62.76 0 0
(g) 94.0 393.296
(s) 0.0 0 56.5 236.396
(g) 406.0 1698.704 188.1 787.0104 366.0 1531.344

Isotopes

Nuklid Masse 10 Halbwertzeit 10 Kernspin 10 Bindungsenergie
206Ac 206.01450(8) 25(7) ms (3+) 1,583.74 MeV
207Ac 207.01195(6) 31(8) ms [27(+11-6) ms] 9/2-# 1,591.82 MeV
208Ac 208.01155(6) 97(16) ms [95(+24-16) ms] (3+) 1,599.89 MeV
209Ac 209.00949(5) 92(11) ms (9/2-) 1,617.27 MeV
210Ac 210.00944(6) 350(40) ms 7+# 1,625.35 MeV
211Ac 211.00773(8) 213(25) ms 9/2-# 1,633.42 MeV
212Ac 212.00781(7) 920(50) ms 6+# 1,641.49 MeV
213Ac 213.00661(6) 731(17) ms (9/2-)# 1,649.56 MeV
214Ac 214.006902(24) 8.2(2) s (5+)# 1,657.63 MeV
215Ac 215.006454(23) 0.17(1) s 9/2- 1,665.70 MeV
216Ac 216.008720(29) 0.440(16) ms (1-) 1,673.77 MeV
217Ac 217.009347(14) 69(4) ns 9/2- 1,681.84 MeV
218Ac 218.01164(5) 1.08(9) μs (1-)# 1,680.60 MeV
219Ac 219.01242(5) 11.8(15) μs 9/2- 1,688.67 MeV
220Ac 220.014763(16) 26.36(19) ms (3-) 1,696.74 MeV
221Ac 221.01559(5) 52(2) ms 9/2-# 1,704.81 MeV
222Ac 222.017844(6) 5.0(5) s 1- 1,712.89 MeV
223Ac 223.019137(8) 2.10(5) min (5/2-) 1,720.96 MeV
224Ac 224.021723(4) 2.78(17) h 0- 1,719.71 MeV
225Ac 225.023230(5) 10.0(1) d (3/2-) 1,727.79 MeV
226Ac 226.026098(4) 29.37(12) h (1)(-#) 1,735.86 MeV
227Ac 227.0277521(26) 21.772(3) a 3/2- 1,743.93 MeV
228Ac 228.0310211(27) 6.15(2) h 3+ 1,742.68 MeV
229Ac 229.03302(4) 62.7(5) min (3/2+) 1,750.76 MeV
230Ac 230.03629(32) 122(3) s (1+) 1,758.83 MeV
231Ac 231.03856(11) 7.5(1) min (1/2+) 1,766.90 MeV
232Ac 232.04203(11) 119(5) s (1+) 1,765.65 MeV
233Ac 233.04455(32)# 145(10) s (1/2+) 1,773.73 MeV
234Ac 234.04842(43)# 44(7) s 1,781.80 MeV
235Ac 235.05123(38)# 40# s 1/2+# 1,780.55 MeV
236Ac 236.05530(54)# 2# min 1,788.62 MeV
Werte markiert # sind nicht rein aus experimentellen Daten abgeleitet, aber zumindest teilweise von der systematischen Trends. Dreht mit schwachen Zuordnung Argumente in Klammern eingeschlossen sind. 10

Fülle

Erde -  Kruste:  0.00000000055 mg/kg = 0.000000000000055% 11

Sicherheitsinformation


Datenblatt zur Materialsicherheit - ACI Alloys, Inc.

Für mehr Informationen

Externe Links:

Zeitschriften:
(1) A. Debierne, C. R. Acad. Sci. 129, 593 (1899)
(2) F.O. Geisel, Ber. 55, 3608 (1902)
(3) J.G. Stites, Jr. et al., J. Am. Chem. Soc. 77, 237 (1955)
(4) J.D. Farr et al., J. Inorg. Nucl. Chem. 18, 42 (1961)
(5) O. Hahn, Ber. 40, 1462 (1907)

Quellen

(1) - Lide, David R. CRC Handbook of Chemistry and Physics, 83rd ed.; CRC Press: Boca Raton, FL, 2002; p 4:3.
(2) - Lide, David R. CRC Handbook of Chemistry and Physics, 83rd ed.; CRC Press: Boca Raton, FL, 2002; p 4:132.
(3) - Lide, David R. CRC Handbook of Chemistry and Physics, 84th ed.; CRC Press: Boca Raton, FL, 2002; p 4:39-4:96.
(4) - Dean, John A. Lange's Handbook of Chemistry, 11th ed.; McGraw-Hill Book Company: New York, NY, 1973; p 4:8-4:149.
(5) - Lide, David R. CRC Handbook of Chemistry and Physics, 84th ed.; CRC Press: Boca Raton, FL, 2002; p 10:147-10:148.
(6) - Lide, David R. CRC Handbook of Chemistry and Physics, 83rd ed.; CRC Press: Boca Raton, FL, 2002; p 10:178 - 10:180.
(7) - Lide, David R. CRC Handbook of Chemistry and Physics, 83rd ed.; CRC Press: Boca Raton, FL, 2002; p 4:133.
(8) - Lide, David R. CRC Handbook of Chemistry and Physics, 83rd ed.; CRC Press: Boca Raton, FL, 2002; pp 6:193, 12:219-220.
(9) - Lide, David R. CRC Handbook of Chemistry and Physics, 83rd ed.; CRC Press: Boca Raton, FL, 2002; pp 6:123-6:137.
(10) - Lide, David R. CRC Handbook of Chemistry and Physics, 83rd ed.; CRC Press: Boca Raton, FL, 2002; pp 6:107-6:122.
(11) - Lide, David R. CRC Handbook of Chemistry and Physics, 84th ed.; CRC Press: Boca Raton, FL, 2002; p 5:5.
(12) - Atomic Mass Data Center. http://amdc.in2p3.fr/web/nubase_en.html (accessed July 14, 2009).
(13) - Lide, David R. CRC Handbook of Chemistry and Physics, 83rd ed.; CRC Press: Boca Raton, FL, 2002; p 14:17.