Basic Information
The melting point of lanthanum is 920* C (1688* F), the boiling point of lanthanum is 3464* C (6267* F). Lanthanum's natural density is 6.15g/mL. Lanthanum is a silvery metal that is soft enough to be cut with a knife. It is one the most reactive of all the rare-earth metals, second only to europium, and it reacts when it comes in contact with dry air. It oxides very rapidly when exposed to oxygen, so it is rare to see this metal with its original luster.
Atomic Structure
Lanthanum has 57 protons and 82 neutrons in its nucleus, and it has 57 electrons in its electron cloud. Its electron configuration is as follows:
[XE]5d26s1