All chemical elements

Symbol

I

Atomic number

53

Chemical property

Reactive nonmetal

Origin o the name

French iode (after the Greek ioeides, 'violet')

Group

17

Period

5

Atomic weight (u)

126.90447

Atomic weight uncertainty (u)

0.00003

Density (g/cm³)

4.93

Melting point (K)

386.85

Boiling point (K)

457.4

Heat capacity (J/(g·K))

0.214

Electro-negativity

2.66

Abundance in earth's crust (mg/kg)

0.45