Seaborgium (Sg)

Seaborgium was the first element named after a living person, which IUPAC initially refused to allow — it proposed rutherfordium for 106 instead, and the American Chemical Society objected loudly enough that the rule was changed in 1997. Glenn Seaborg thus spent two years as the only living person with an element, and remarked that it was better than winning the Nobel Prize, which he had already done. Chemistry on seven atoms in 1997 showed it forms a volatile oxychloride like molybdenum and tungsten, confirming it as a group 6 metal.

Properties

Atomic number

106

Symbol

Sg

Mass number of most stable isotope

[269]

Category

Transition metal

Group

6

Period

7

Block

d-block

Electron configuration

[Rn] 7s² 5f¹⁴ 6d⁴

Electrons per shell

2, 8, 18, 32, 32, 12, 2

Oxidation states

+6, +5, +4, +3

Discovered

1974 by Albert Ghiorso, Glenn Seaborg and colleagues at Berkeley

Electron configuration

Full

1s² 2s² 2p⁶ 3s² 3p⁶ 4s² 3d¹⁰ 4p⁶ 5s² 4d¹⁰ 5p⁶ 6s² 4f¹⁴ 5d¹⁰ 6p⁶ 7s² 5f¹⁴ 6d⁴

Noble gas shorthand

[Rn] 7s² 5f¹⁴ 6d⁴

Shells

K: 2 · L: 8 · M: 18 · N: 32 · O: 32 · P: 12 · Q: 2

What it is used for

• Research only; no application outside the laboratory

Hazards

• Intensely radioactive; exists only as individual atoms in an accelerator

Melting point, boiling point, density and electronegativity are omitted: no measurement is possible. The mass given is the mass number of seaborgium-269, the longest-lived at roughly 14 minutes.

Several physical properties are not listed for seaborgium because no bulk sample has ever existed. Only a handful of atoms have been produced, often with half-lives measured in seconds, so published melting points and densities for elements in this range are calculations rather than measurements. They are omitted rather than presented as observed values.

Neighbours in the table

Group 6

Elements in the same group share their outer electron count, which is why they behave similarly in reactions. Seaborgium sits in group 6 with chromium, molybdenum, tungsten.