Lanthanum (La)
Lanthanum (La, element 57) is a lanthanide in group 3, period 6. Atomic mass 138.905, electron configuration [Xe] 5d¹ 6s², uses and facts.
About Lanthanum
Lanthanum is a lanthanide with the symbol La and atomic number 57. It is a solid at room temperature, and it sits in group 3, period 6 of the periodic table. Lanthanum was discovered in 1839 by Carl Gustaf Mosander.
Lanthanum key facts
- Atomic number: 57
- Symbol: La
- Atomic mass: 138.905 u
- Category: lanthanide
- Group: 3
- Period: 6
- State at room temperature: solid
- Electron configuration: [Xe] 5d¹ 6s²
- Electronegativity (Pauling): 1.1
- Melting point: 1193 K (919.85 °C)
- Boiling point: 3737 K (3463.85 °C)
- Density: 6.162 g/cm³
- Common oxidation states: +2, +3
Electron configuration
The electron configuration of lanthanum is [Xe] 5d¹ 6s². The part in brackets is the noble gas core; the rest shows how the outer electrons fill their subshells.
Uses of lanthanum
- Camera lenses
- Hydrogen storage
- Catalysts
Did you know?
Lanthanum oxide is used in high-quality camera and telescope lenses.
Other elements in group 3 and neighbours
Frequently asked questions
What is the atomic number of lanthanum?
The atomic number of lanthanum is 57, which means every lanthanum atom has 57 protons.
What is the electron configuration of lanthanum?
The electron configuration of lanthanum is [Xe] 5d¹ 6s².
What group and period is lanthanum in?
Lanthanum is a lanthanide in group 3, period 6.
What state is lanthanum at room temperature?
Lanthanum is a solid at room temperature.
What is lanthanum used for?
Lanthanum is used for camera lenses, hydrogen storage, catalysts.