57 La
Lanthanide
Lanthanum
Used in camera lenses.
Properties of Lanthanum
- Atomic number (Z)
- 57
- Symbol
- La
- Atomic mass
- 138.91 g/mol
- Category
- Lanthanide
- Group
- 3
- Period
- 6
- Electron configuration
- [Xe] 5d¹ 6s²
- Electronegativity (Pauling)
- 1.1
- Atomic radius
- 226 pm
- First ionization energy
- 538 kJ/mol
- Melting point
- 1193 K (919.9 °C)
- Boiling point
- 3737 K (3463.8 °C)
- Density
- 6.145 g/cm³
- Phase at 25 °C
- Solid
- Discovered
- Discovered in 1839
Frequently asked questions
What is Lanthanum?
Lanthanum (La) is a lanthanide, element number 57 on the periodic table. Used in camera lenses.
What is the atomic number and atomic mass of Lanthanum?
Lanthanum has atomic number 57 and an atomic mass of about 138.91 g/mol.
What is the electron configuration of Lanthanum?
The electron configuration of Lanthanum is [Xe] 5d¹ 6s².
Where is Lanthanum on the periodic table?
Lanthanum sits in group 3, period 6, and is classified as a lanthanide.