Lanthanum (La)

About Lanthanum

Lanthanum is a chemical element with the symbol La and atomic number 57, meaning every atom has 57 protons in its nucleus. It is classed as Lanthanide and is a solid at room temperature. Its atomic mass is about 138.905 atomic mass units (u).

On the periodic table, Lanthanum sits in group 3, period 6 (lanthanide series), which determines how many electron shells it has and how it tends to react with other elements.

Uses of Lanthanum

In daily life and industry, Lanthanum is used for Camera lenses. These uses are closely tied to the typical properties of elements in the Lanthanide category.

Electron Structure of Lanthanum

Using a simplified electron shell model (at most 2 electrons in the first shell, 8 in the second, 18 in the third, and so on), Lanthanum has 4 electron shells, with an approximate arrangement of 2, 8, 18, 29 electrons from the innermost shell to the outermost. This is a simplified learning model, not the full electron configuration that accounts for the s, p, d and f subshells.

Explore Other Elements

Want to see another element or try the element symbol quiz? Go back to the Interactive Periodic Table to explore all 118 chemical elements.

Frequently Asked Questions