Mendeleev.com
Understanding the element
Lanthanum (La) is chemical element 57. It belongs to the lanthanoids, and its reference state at room temperature is a solid. Those basic facts are a useful starting point for its chemistry and applications.
Where do we encounter it?
In practice, it turns up most often in optical lenses, batteries and catalysts.
optical lensesbatteriescatalysts
Standard atomic weight138.90547(7)
What its position in the table tells us
Lanthanum sits in period 6, group 3 and the D block. That location is useful because neighbouring elements often share trends in valence electrons, oxidation states and bonding behaviour.
Worth remembering
Lanthanum has a characteristic place in the periodic table that helps explain both its chemistry and its practical uses
Lanthanum has a characteristic place in the periodic table that helps explain both its chemistry and its practical uses