All chemical elements

Symbol

Tl

Atomic number

81

Chemical property

Post-​transition metal

Origin o the name

the Greek thallos, 'green twig'

Group

13

Period

6

Atomic weight (u)

204.38

Density (g/cm³)

11.85

Melting point (K)

577

Boiling point (K)

1746

Heat capacity (J/(g·K))

0.129

Electro-negativity

1.62

Abundance in earth's crust (mg/kg)

0.85