57

La

Lanthanum

138.91

Lathanide
Solid

Discovery

Mosander, Carl Gustav (1839)

Etymology

Greek

Meaning

To lie hidden

Electron configuration

Electron configuration

Crystal structure

Crystal structure

Double hexagonal close-packed

Physical Properties

Phase

  (at 21 °C and 101.325 kPa)

Solid

Melting point

  (at 101.325 kPa)

920.0 °C

1193.15 K

Boiling point

  (at 101.325 kPa)

1140.0 °C

1413.15 K

Density

  (at 21 °C and 101.325 kPa)

6.15 g/cm3

Electronegativity

1.10