Periodex

General properties

Group

group 15 (pnictogens)

Period

period 5

Category

metalloids

Standard atomic weight

121.760(1)

Melting point

903.78 K (630.63 °C)

Boiling point

1908 K (1635 °C)

Phase at STP

solid

Additional properties

Block

p-block

Electron configuration

[Kr] 4d¹⁰ 5s² 5p³

Electrons per shell

2, 8, 18, 18, 5

Electronegativity

2.05

Density

6.697 g/cm³

Oxidation states

−3, −2, −1, 0, +1, +2, +3, +4, +5 (an amphoteric oxide)

CAS Number

7440-36-0

Natural isotopes

Discovery history

Discovered by

ancient civilizations

Year of discovery

before 815 CE

Origin of name

The Greek 'anti - monos', meaning not alone (stibium in Latin)