071Lanthanide · Group 3 · Period 6
Lutetium
Lutetium (Lu) is element 71, a lanthanide in the d-block — group 3, period 6. It is a solid at room temperature with 6 electron shells (2, 8, 18, 32, 9, 2) and an atomic mass of 174.96681 u.
- Atomic mass
- 175.0 u
- Phase · STP
- solid
- Melting
- 1925 K · 1652 °C
- Boiling
- 3675 K · 3402 °C
- Electronegativity
- 1.27
- Density
- 9.841 g/cm³
Photograph — Jurii, CC BY 3.0 <https://creativecommons.org/licenses/by/3.0>, via Wikimedia Commons, source: https://images-of-elements.com/lutetium.php
Identity
- Atomic number
- 71
- Standard atomic weight
- 175.0 u
- Category
- Lanthanide
- Group
- 3
- Period
- 6
- Block
- d-block
- Oxidation states
- +3
Physical properties
- Melting point
- 1925 K · 1652 °C
- Boiling point
- 3675 K · 3402 °C
- Density
- 9.841 g/cm³
- Molar heat capacity
- 26.86 J/(mol·K)
- Atomic radius
- 221 pm
- Electron affinity
- 33.4 kJ/mol
Atomic structure
71protons
104neutrons
71electrons
2valence e⁻
- Noble-gas notation
- [Xe] 4f14 5d1 6s2
- Full configuration
- 1s2 2s2 2p6 3s2 3p6 4s2 3d10 4p6 5s2 4d10 5p6 6s2 4f14 5d1
- Electrons per shell
- 2, 8, 18, 32, 9, 2
Periodic trends
Where Lutetium ranks across all 118 elements.
Ionization energies
Energy to remove each successive electron (kJ/mol).
523.51
1.3k2
2.0k3
4.4k4
6.4k5
Successive ionization energies (kJ/mol, log scale).
Discovery
- Discovered
- 1907
- Discovered by
- Georges Urbain
- Named by
- —
- Appearance
- silvery white