Lutetium (Lu)
Lutetium is element 71, a lanthanide in period 6, group 3 of the periodic table. At room temperature it is a solid.
Electron configuration [Xe] 4f14 5d1 6s2
Electrons per shell 2, 8, 18, 32, 9, 2
Lutetium data
| Atomic number | 71 |
|---|---|
| Symbol | Lu |
| Atomic mass | 174.967 u |
| Category | Lanthanide |
| Group | 3 |
| Period | 6 |
| Block | f |
| State at 25 °C | solid |
| Melting point | 1936 K (1662.9 °C) |
| Boiling point | 3675 K (3401.9 °C) |
| Density | 9.841 g/cm³ |
| Electronegativity (Pauling) | 1.27 |
| Atomic radius | 160 pm |
| 1st ionization energy | 524 kJ/mol |
| Electron affinity | -50 kJ/mol |
| Oxidation states | +3 |
| Common ion charge | 3+ |
| Discovered | 1907 |
Orbital diagram
Each box is one orbital holding up to two electrons of opposite spin. Following Hund’s rule, electrons spread out singly across a subshell before pairing.
Work through lutetium’s configuration and its ions →
Where lutetium sits
Lutetium belongs to the lanthanides. Its Pauling electronegativity of 1.27 is mid-range; see the electronegativity chart and periodic trends for context. To use its mass in a calculation, try the molar mass calculator.
Lutetium FAQ
What is the electron configuration of lutetium?
Lutetium (Z = 71) has the configuration 1s2 2s2 2p6 3s2 3p6 3d10 4s2 4p6 4d10 5s2 5p6 4f14 5d1 6s2. In noble-gas shorthand that is [Xe] 4f14 5d1 6s2.
How many valence electrons does lutetium have?
3 (2 outer s + 1 d electrons; 2 in the outermost shell).
What is the atomic mass of lutetium?
The standard atomic weight of lutetium is 174.967 u, so one mole weighs 174.967 g.
Is lutetium a metal?
Yes. Lutetium is a lanthanide.
What is the charge of a lutetium ion?
Lutetium most commonly forms Lu3+.