Seaborgium
Transition metal · Period 7 · Group 6 · d-block
The first element named after a living person
- Atomic mass
- 269 u
- State at 25 °C
- Solid
- Electronegativity
- —
- Melting point
- —
- Boiling point
- —
- Configuration
- *[Rn] 5f14 6d4 7s2
Nucleus drawn at reduced count for clarity. Drag to rotate.
Seaborgium, explained
Video lesson in production
Bhavya’s explainer for this element will play here.
Overview
Seaborgium belongs to group 6, beneath chromium, molybdenum and tungsten, with a predicted 7s2 6d4 configuration. Like tungsten it reaches a +6 oxidation state using all six valence electrons. Experiments at GSI in the 1990s showed it forms the volatile oxychloride SgO2Cl2 and, in solution, oxo-anions that behave like those of molybdenum and tungsten, confirming its placement in the table.
In 2014 an international team at RIKEN made seaborgium hexacarbonyl, Sg(CO)6, the first organometallic-type compound of any superheavy element. Its volatility and adsorption matched tungsten hexacarbonyl, W(CO)6, closely, as relativistic calculations had predicted. That experiment showed that bonding involving 6d orbitals can be probed even when only a handful of molecules exist. The longest-lived confirmed isotope, seaborgium-269, has a half-life of around 14 minutes.
Discovery
Albert Ghiorso, Kenneth Hulet and colleagues at Berkeley and Livermore made element 106 in 1974 by bombarding californium-249 with oxygen-18; Yuri Oganessian's team at Dubna reported it the same year by fusing lead with chromium-54. The Americans proposed seaborgium for Glenn Seaborg, who helped discover ten transuranium elements, beginning with plutonium. IUPAC first objected because Seaborg was alive, then approved the name in 1997.
- Where it’s found
- Seaborgium does not occur in nature; it is made in accelerators by fusing light ions with actinide targets or heavier ions with lead.
- What it’s used for
- Superheavy carbonyl chemistry
- Group 6 trend studies
- Relativistic effects research
- Nuclear structure research
- In living things
- Seaborgium has no biological role; it is radioactive and exists only as individual atoms.
- Safety
- Radioactive and made only a few atoms at a time; it decays within seconds to minutes.
How it compares
Where Seaborgium sits among all 118 elements on the trends that shape the table.
- ElectronegativityNo data
Not measured for this element
- Ionization energyNo data
Not measured for this element
- Atomic radiusNo data
Not measured for this element
- Electron affinityNo data
Not measured for this element
- Density35g/cm³
#4 of 114 elements with data · predicted
- Melting pointNo data
Not measured for this element
- Density
- 35 g/cm³
- Atomic radius
- —
- Covalent radius
- —
- Molar heat
- —
- Appearance
- —
- Discovered by
- Lawrence Berkeley National Laboratory
Inside the atom
106 electrons arranged in 7 shells: 2 · 8 · 18 · 32 · 32 · 12 · 2.
Orbital diagram
1s2 2s2 2p6 3s2 3p6 4s2 3d10 4p6 5s2 4d10 5p6 6s2 4f14 5d10 6p6 7s2 5f14 6d4 · shorthand *[Rn] 5f14 6d4 7s2
- 1s2
- 2s2
- 2p6
- 3s2
- 3p6
- 4s2
- 3d10
- 4p6
- 5s2
- 4d10
- 5p6
- 6s2
- 4f14
- 5d10
- 6p6
- 7s2
- 5f14
- 6d4
Each box is an orbital holding up to two electrons of opposite spin. Highlighted subshells hold the valence electrons that decide how Seaborgium bonds.
Signature reactions
How the first atoms were made, and how they fall apart.
Nuclear · Fusion-evaporation
Berkeley-Livermore synthesis
Oxygen-18 fuses with californium-249 and four neutrons evaporate. The team identified seaborgium-263 by linking its alpha decays to rutherfordium-259 and nobelium-255.
Conditions: oxygen-18 beam on californium-249, Berkeley SuperHILAC, 1974
Nuclear · Cold fusion
Dubna cold fusion
Oganessian's group pioneered fusing medium-mass ions with lead, which forms a cooler compound nucleus that loses fewer neutrons and survives more often. This cold-fusion approach later produced elements 107 to 113.
Conditions: chromium-54 beam on lead-208, Dubna, 1974
Synthesis · Carbonyl formation
Seaborgium hexacarbonyl
Seaborgium atoms recoiling from the target were stopped in a carbon monoxide atmosphere and formed volatile Sg(CO)6, which was carried to detectors along a chromatography column. The measured behavior matched tungsten hexacarbonyl, as predicted.
Conditions: single recoiling atoms in helium/CO gas, RIKEN, 2014
Where you’ll meet it
Glenn T. Seaborg
The Nobel laureate who reshaped the periodic table with the actinide concept gives element 106 its name.
Photo: Wikimedia Commons
Tungsten hexacarbonyl
Seaborgium's carbonyl Sg(CO)6 behaves like this tungsten compound, its lighter group 6 analog.
Photo: Wikimedia Commons
Lawrence Livermore National Laboratory
Livermore scientists worked with Berkeley on the 1974 seaborgium discovery.
Photo: Wikimedia Commons
Lawrence Berkeley National Laboratory
Seaborg's home institution made element 106 with its SuperHILAC accelerator.
Photo: Wikimedia Commons
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Research
No research on Seaborgium yet
When Bhavya publishes a project that studies Seaborgium, it will be linked here.