Lanthanum

Lanthanide

Symbol: La

Atomic Number: 57

Standard State: Solid

Atomic Mass: 138.9055

Electron Configuration: [Xe]6s2 5d1

Electronegativity: 1.1

Atomic Radius: 240

Ionization Energy: 5.577

Melting Point: 1191

Boiling Point: 3737

Density: 6.15

Year Discovered: 1839