SEABORGIUM

Introduction

Atomic Number: 106
Group: 6 or VI B
Atomic Weight: 266
Period: 7
CAS Number: 54038-81-2

Classification

Chalcogen
Halogen
Noble Gas
Lanthanoid
Actinoid
Rare Earth Element
Platinum Group Metal
Transuranium
No Stable Isotopes
Solid
Liquid
Gas
Solid (Predicted)

Description • Uses/Function

The discovery of Element 106 took place in 1974 almost simultaneously at the Lawrence-Berkeley Laboratory and at the Joint Institute for Nuclear Research at Dubna (near Moscow). The Berkeley Group, under direction of Ghiorso, used the Super-Heavy Ion Linear Accelerator (Super HILAC) as a source of heavy oxygen-18O ions to bombard a 259 microgram target of californium-249. This resulted in the production and positive identification of Element 106-263, which decayed with a half-life of 0.9 ± 0.2 s by the emission of alpha particles. The Dubna Team, directed by Flerov and Organessian, produced heavy ions of chromium-54 with their 310-cm heavy-ion cyclotron to bombard lead-207 and lead-208 and found a product that decayed with a half-life of 7 ms. They assigned Element 106-259 to this isotope. It is now thought six isotopes of Element 106 have been identified. Two of the isotopes are believed to have half-lives of about 30 s. In 1997, IUPAC adopted the name seaborgium for Element 106. 1

Physical Properties

Density:   g/cm3

* - at 1 atm

Electron Configuration

Electron Configuration: [Rn] 7s2 5f14 6d4
Block: d
Highest Occupied Energy Level: 7
Valence Electrons: 

Quantum Numbers:

n = 6
ℓ = 2
m = 1
ms = +½

Bonding

Isotopes

Nuclide Mass 2 Half-Life 2 Nuclear Spin 2 Binding Energy
258Sg 258.11317(45)# 3.3(10) ms [2.9(+13-7) ms] 0+ 1,897.00 MeV
259Sg 259.11450(19)# 580(210) ms [0.48(+28-13) s] 1/2+# 1,905.08 MeV
260Sg 260.11442(4) 3.8(8) ms 0+ 1,913.15 MeV
261Sg 261.11612(14)# 230(60) ms 7/2+# 1,921.22 MeV
262Sg 262.1164(3)# 8(3) ms [6.9(+38-18) ms] 0+ 1,929.29 MeV
263Sg 263.11832(13)# 1.0(2) s 9/2+# 1,937.36 MeV
264Sg 264.11893(30)# 0.4# s 0+ 1,945.43 MeV
265Sg 265.12111(6) 8(3) s 3/2+# 1,944.19 MeV
266Sg 266.12207(31)# 21(6) s 0+ 1,952.26 MeV
267Sg 267.12443(29)# 19 ms 1,960.33 MeV
268Sg 268.12561(58)# 30# s 0+ 1,968.40 MeV
269Sg 269.12876(70)# 35(23) s 1,976.47 MeV
270Sg 270.13033(66)# 10# min 0+ 1,975.23 MeV
271Sg 271.13347(70)# 2.4(+43-10) min 1,983.30 MeV
272Sg 272.13516(82)# 1# h 0+ 1,991.37 MeV
273Sg 273.13822(71)# 1# min 1,999.44 MeV
Values marked # are not purely derived from experimental data, but at least partly from systematic trends. Spins with weak assignment arguments are enclosed in parentheses. 2

Abundance

Safety Information


Material Safety Data Sheet - ACI Alloys, Inc.

For More Information

External Links:

Sources

(1) - Lide, David R. CRC Handbook of Chemistry and Physics, 83rd ed.; CRC Press: Boca Raton, FL, 2002; p 4:28.
(2) - Lide, David R. CRC Handbook of Chemistry and Physics, 83rd ed.; CRC Press: Boca Raton, FL, 2002; pp 6:123-6:137.
(3) - Lide, David R. CRC Handbook of Chemistry and Physics, 83rd ed.; CRC Press: Boca Raton, FL, 2002; pp 6:107-6:122.
(4) - Atomic Mass Data Center. http://amdc.in2p3.fr/web/nubase_en.html (accessed July 14, 2009).