NOBELIUM

introduction

Numéro atomique: 102
Groupe: Aucun
Poids atomique: 259
Période: 7
Numero CAS: 10028-14-5

Classification

chalcogènes
Halogène
Gaz rare
lanthanides
actinides
Rare Earth Element
Groupe Platine Métal
Transuranium
Pas d'isotopes stables
Solide
Liquide
Gaz
Solide (prédit)

La description • Usages / Fonction

Nobelium was unambiguously discovered and identified in April 1958 at Berkeley by A. Ghiorso, T. Sikkeland, J. R. Walton, and G. T. Seaborg, who used a new double-recoil technique. A heavy-ion linear accelerator (HILAC) was used to bombard a thin target of curium (95% curium-244 and 4.5% curium-246) with carbon-12 ions to produce Element 102-254 according to the curium-246 (carbon-12, 4 neutrons) reaction. Earlier in 1957 workers of the U.S., Britain, and Sweden announced the discovery of an isotope of Element 102 with a 10-min half-life at 8.5 MeV, as a result of bombarding curium-244 with carbon-13 nuclei. On the basis of this experiment the name nobelium was assigned and accepted by the Commission on Atomic Weights of the International Union of Pure and Applied Chemistry. The acceptance of the name was premature, for both Russian and American efforts now completely rule out the possibility of any isotope of Element 102 having a half-life of 10 min in the vicinity of 8.5 MeV. Early work in 1957 on the search for this element, in Russia at the Kurchatov Institute, was marred by the assignment of 8.9 ± 0.4 MeV alpha radiation with a half-life of 2 to 40 sec, which was too indefinite to support claim to discovery. Confirmatory experiments at Berkeley in 1966 have shown the existence of Element 102-254 with a 55-s half-life, Element 102-252 with a 2.3-s half-life, and Element 102-257 with a 25-s half-life. Twelve isotopes are now recognized, one of which — Element 102-255 has a half-life of 3.1 min. In view of the discover’s traditional right to name an element, the Berkeley group, in 1967, suggested that the hastily given name nobelium, along with the symbol No, be retained. 1

Propriétés physiques

Point de fusion:2*  827 °C = 1100.15 K = 1520.6 °F
Point d'ébullition:2
sublimation point:2 
Triple point:2 
Point critique:2 
Densité:   g/cm3

* - at 1 atm

Configuration de l'électron

Configuration de l'électron:  *[Rn] 7s2 5f14
Bloque: f
Plus haut niveau d'énergie occupés: 7
Électrons de valence: 2

Nombres quantiques:

n = 5
ℓ = 3
m = 3
ms = -½

Bonding

ionisation potentiel   eV 3  kJ/mol  
ionisation potentiel   eV 3  kJ/mol  
ionisation potentiel   eV 3  kJ/mol  
1 6.65    641.6

Thermochimie

Chaleur spécifique: 
Conductivité thermique: 10 (W/m)/K, 27°C 4
Température de fusion: 
Chaleur de vaporisation: 
État de la matière Enthalpie de formation (ΔHf°)5 Entropy (S°)5 Gibbs Free Energy (ΔGf°)5
(kcal/mol) (kJ/mol) (cal/K) (J/K) (kcal/mol) (kJ/mol)
(g) 21.57 90.24888 50.347 210.651848 20.69 86.56696

isotopes

Nuclide Masse 6 Demi vie 6 Spin nucléaire 6 Énergie de liaison
248No 248.08660(32)# <2 μs 0+ 1,847.36 MeV
249No 249.08783(37)# 57(12) μs [54(+15-10) μs] 5/2+# 1,855.44 MeV
250No 250.08751(22)# 5.7(8) μs 0+ 1,863.51 MeV
251No 251.08901(19)# 0.78(2) s 7/2+# 1,871.58 MeV
252No 252.088977(14) 2.27(14) s 0+ 1,879.65 MeV
253No 253.09068(11)# 1.62(15) min (9/2-)# 1,878.41 MeV
254No 254.090955(19) 51(10) s 0+ 1,886.48 MeV
255No 255.093241(11) 3.1(2) min (1/2+) 1,894.55 MeV
256No 256.094283(8) 2.91(5) s 0+ 1,902.62 MeV
257No 257.096877(23) 25(2) s (7/2+) 1,910.69 MeV
258No 258.09821(22)# 1.2(2) ms 0+ 1,918.76 MeV
259No 259.10103(11)# 58(5) min (9/2+)# 1,917.52 MeV
260No 260.10264(22)# 106(8) ms 0+ 1,925.59 MeV
261No 261.10575(32)# 3# h 3/2+# 1,933.66 MeV
262No 262.10730(48)# ~5 ms 0+ 1,941.73 MeV
263No 263.11055(53)# 20# min 1,940.49 MeV
264No 264.11235(69)# 1# min 0+ 1,948.56 MeV
Les valeurs marquées # ne sont pas purement dérivées des données expérimentales, mais au moins en partie des tendances systématiques. Spins avec de faibles arguments d'affectation sont entre parenthèses. 6

Réactions

Abondance

Information de sécurité


Fiche signalétique - ACI Alloys, Inc.

Pour plus d'informations

Liens externes:

Sources

(1) - Lide, David R. CRC Handbook of Chemistry and Physics, 83rd ed.; CRC Press: Boca Raton, FL, 2002; p 4:21.
(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, 83rd ed.; CRC Press: Boca Raton, FL, 2002; p 10:178 - 10:180.
(4) - Lide, David R. CRC Handbook of Chemistry and Physics, 83rd ed.; CRC Press: Boca Raton, FL, 2002; pp 6:193, 12:219-220.
(5) - Lide, David R. CRC Handbook of Chemistry and Physics, 83rd ed.; CRC Press: Boca Raton, FL, 2002; pp 6:123-6:137.
(6) - Lide, David R. CRC Handbook of Chemistry and Physics, 83rd ed.; CRC Press: Boca Raton, FL, 2002; pp 6:107-6:122.
(7) - Dean, John A. Lange's Handbook of Chemistry, 12th ed.; McGraw-Hill Book Company: New York, NY, 1979; p 9:4-9:94.
(8) - Atomic Mass Data Center. http://amdc.in2p3.fr/web/nubase_en.html (accessed July 14, 2009).
(9) - Zumdahl, Steven and Zumdahl, Susan A. Chemistry 9th ed.; Brooks/Cole: Belmont, CA, 2014; p 132.
(10) - Halka, Monica and Nordstrom, Brian. Metals & Metalloids; Infobase Publishing: New York, NY, 2011; pg. 96.
(11) - Ebbing, Darrell D. General Chemistry 3rd ed.; Houghton Mifflin Company: Boston, MA, 1990; p 135.
(12) - Swaddle, T.W. Inorganic Chemistry; Academic Press: San Diego, 1997; p 360.
(13) - Ebbing, Darrell D. General Chemistry 3rd ed.; Houghton Mifflin Company: Boston, MA, 1990; pp 223-4, 302.
(14) - Ebbing, Darrell D. General Chemistry 3rd ed.; Houghton Mifflin Company: Boston, MA, 1990; pp 135, 138, 194, 210, 219, 222, 224, 227.
(15) - Kotz, John C., Treichel, Paul, and Weaver, Gabriela. Chemistry & Chemical Reactivity 6th ed.; Thomson Brooks/Cole: Belmont, CA, 2006; p 166.
(16) - Ebbing, Darrell D. General Chemistry 3rd ed.; Houghton Mifflin Company: Boston, MA, 1990; pp 219, 302.
(17) - Ebbing, Darrell D. General Chemistry 3rd ed.; Houghton Mifflin Company: Boston, MA, 1990; p 138.
(18) - Ebbing, Darrell D. General Chemistry 3rd ed.; Houghton Mifflin Company: Boston, MA, 1990; pp 211, 219.
(19) - Halka, Monica and Nordstrom, Brian. Metals & Metalloids; Infobase Publishing: New York, NY, 2011; pg. 49.