Periodex

General properties

Group

group 13

Period

period 6

Category

post-transition metals

Standard atomic weight

204.38

[204.382, 204.385]

Melting point

577 K (304 °C)

Boiling point

1746 K (1473 °C)

Phase at STP

solid

Additional properties

Block

p-block

Electron configuration

[Xe] 4f¹⁴ 5d¹⁰ 6s² 6p¹

Electrons per shell

2, 8, 18, 32, 18, 3

Electronegativity

1.62

Density

11.85 g/cm³

Oxidation states

−5, −2, −1, +1, +2, +3

CAS Number

7440-28-0

Natural isotopes

Discovery history

Discovered by

William Crookes

Year of discovery

1861

Origin of name

The Greek 'thallos', meaning a green twig