Periodex

General properties

Group

n/a

Period

period 7

Category

actinoids

Standard atomic weight

-

Melting point

912.5 K (639.4 °C)

Boiling point

3505 K (3232 °C)

Phase at STP

solid

Additional properties

Block

f-block

Electron configuration

[Rn] 5f⁶ 7s²

Electrons per shell

2, 8, 18, 32, 24, 8, 2

Electronegativity

1.28

Density

19.816 g/cm³

Oxidation states

+1, +2, +3, +4, +5, +6, +7 (an amphoteric oxide)

CAS Number

7440-07-5

Natural isotopes

Discovery history

Discovered by

Glenn T. Seaborg, Arthur Wahl, Joseph W. Kennedy ja Edwin McMillan

Year of discovery

1940–1941

Origin of name

Pluto, a dwarf planet in the Solar System