Periodex

General properties

Group

group 16 (chalcogens)

Period

period 5

Category

metalloids

Standard atomic weight

127.60(3)

Melting point

722.66 K (449.51 °C)

Boiling point

1261 K (988 °C)

Phase at STP

solid

Additional properties

Block

p-block

Electron configuration

[Kr] 4d¹⁰ 5s² 5p⁴

Electrons per shell

2, 8, 18, 18, 6

Electronegativity

2.1

Density

6.24 g/cm³

Oxidation states

−2, −1, +1, +2, +3, +4, +5, +6 (a mildly oxide)

CAS Number

13494-80-9

Natural isotopes

Discovery history

Discovered by

Franz-Joseph Müller von Reichenstein

Year of discovery

1782

Origin of name

Earth, the third planet on solar system (with the Latin word tellus)