AKTINIUM

Inleiding

atoomgetal: 89
groep: 3 or III B
atoomgewig: 227
tydperk: 7
CAS nommer: 7440-34-8

klassifikasie

Metal
metaal
metaalagtige
alkalimetaal
Alkali aard metaal
oorgangsmetaal
Chalcogen
halogeen
edelgas
Lanthanoid
Actinoid
Rare Earth Element
Platinumgroepmetaalverwante
transuraan
Geen stabiele isotope
Solied
Liquid
gas
Solied (voorspel)

beskrywing • Gebruike / Function

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

Fisiese eienskappe

Smeltpunt:2*  1051 °C = 1324.15 K = 1923.8 °F
Kookpunt:2* 3198 °C = 3471.15 K = 5788.4 °F
sublimasie Point:2 
Drie Point:2 
kritieke punt:2 
digtheid:3  10 g/cm3

* - at 1 atm

elektronkonfigurasie

elektronkonfigurasie:  *[Rn] 7s2 5f1
Blok: d
Hoogste Besig energievlak: 7
valenselektrone: 

kwantumgetalle:

n = 5
ℓ = 3
m = -3
ms = +½

binding

elektronegatiwiteit (Pauling skaal):4 1.1
Electropositivity (Pauling skaal): 2.9
elektronaffiniteit:5 0.35 eV
oksidasietoestande: +3

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

termochemie

Spesifieke hitte: 0.120 J/g°C 7 = 27.240 J/mol°C = 0.029 cal/g°C = 6.511 cal/mol°C
Termiese geleidingsvermoë: 12 (W/m)/K, 27°C 8
Verhit van Fusion: 
Hitte van verdamping: 
Toestand van materie Entalpie van vorming (ΔHf°)9 entropie (S°)9 Gibbs vrye 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

isotope

nuklied Mis 10 Halflewe 10 kern Spin 10 bindingsenergie
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
Waardes gemerk # is nie suiwer afgelei van eksperimentele data, maar ten minste gedeeltelik uit sistematiese tendense. Draai met 'n swak werkstuk argumente is ingesluit in hakies. 10

oorvloed

aarde -  kors:  0.00000000055 mg/kg = 0.000000000000055% 11

veiligheid inligting

Vir meer inligting

eksterne skakel:

tydskrifte:
(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)

Bronne

(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.