La
Lanthanum138.90547 (7)
Carl Gustav Mosander recognized the element lanthanum in impure cerium nitrate in 1839. His extraction resulted in the oxide lanthana (La2O3). A number of other lanthanides (rare-earths) were later discovered by identification of the impurities in yttrium and cerium compounds.
- Name:Lanthanum
- Symbol: La
- Atomic number: 57
- Atomic weight:138.90547 (7)
- Standard state: solid at 298 K
- Group in periodic table:
- Group name:lanthanoid
- Period in periodic table: 6
- Block in periodic table: f-block
- Classification: Metallic
- lighter flints
- small amounts as an additive are used to produce nodular cast iron
Cold water attacks lanthanum slowly, and hot water attacks it much more rapidly. The metal reacts directly with elemental carbon, nitrogen, boron, selenium, silicon, phosphorus, sulphur, and with halogens.