Periodex

General properties

Group

group 16 (chalcogens)

Period

period 7

Category

unknown

Standard atomic weight

-

Melting point

637–780 K (extrapolated)

Boiling point

1035–1135 K (extrapolated)

Phase at STP

solid (predicted)

Additional properties

Block

p-block

Electron configuration

[Rn] 5f¹⁴ 6d¹⁰ 7s² 7p⁴ (predicted)

Electrons per shell

2, 8, 18, 32, 32, 18, 6

Electronegativity

–

Density

12.9 g/cm³ (predicted)

Oxidation states

(−2), (+2), (+4) (parenthesized: prediction)

CAS Number

54100-71-9

Natural isotopes

Discovery history

Discovered by

Joint Institute for Nuclear Research ו-Lawrence Livermore National Laboratory

Year of discovery

2000

Origin of name

Lawrence Livermore National Laboratory (in Livermore, California) which collaborated with JINR on its synthesis