Lutetium (Lu): electron configuration, atomic mass and facts
Lutetium (Lu) is element 71 of the periodic table, a lanthanide in period 6 (f-block). Its electron configuration is [Xe] 4f14 5d1 6s2, with electrons arranged in shells 2, 8, 18, 32, 9, 2, and its standard atomic weight is 174.97 u.
▶ Watch Lutetium’s electrons orbit in the interactive periodic tableLutetium at a glance
| Symbol | Lu |
|---|---|
| Atomic number | 71 |
| Atomic mass | 174.97 u |
| Category | Lanthanide |
| Group | f-block (no group number) |
| Period | 6 |
| Block | f-block |
| Electron configuration | 1s2 2s2 2p6 3s2 3p6 3d10 4s2 4p6 4d10 4f14 5s2 5p6 5d1 6s2 |
| Noble-gas shorthand | [Xe] 4f14 5d1 6s2 |
| Electrons per shell | 2, 8, 18, 32, 9, 2 |
| Electronegativity (Pauling) | 1.27 |
| State at 20 °C | solid |
Where is Lutetium on the periodic table?
Lutetium is in period 6 of the f-block, the lanthanide row printed below the main table. It has 6 electron shells, and this row is where the 4f subshell fills.
How to work out the electron configuration of Lutetium
Put 71 electrons into subshells in order of rising energy, filling each before starting the next: 1s² (2), 2s² (4), 2p⁶ (10), 3s² (12), 3p⁶ (18), 4s² (20), 3d¹⁰ (30), 4p⁶ (36), 5s² (38), 4d¹⁰ (48), 5p⁶ (54), 6s² (56), 4f¹⁴ (70), 5d¹ (71). In shorthand, [Xe] stands for the 54 electrons of xenon, giving [Xe] 4f¹⁴ 5d¹ 6s².
How electronegative is Lutetium?
Lutetium has a Pauling electronegativity of 1.27, ranking 73 of the 100 elements with a known value (fluorine is highest at 3.98). That is low: it tends to give up electrons and form positive ions.
Frequently asked questions
What is the electron configuration of Lutetium?
The electron configuration of Lutetium (Lu) is 1s2 2s2 2p6 3s2 3p6 3d10 4s2 4p6 4d10 4f14 5s2 5p6 5d1 6s2. In noble-gas shorthand it is written [Xe] 4f14 5d1 6s2.
How many electrons does Lutetium have in each shell?
Lutetium has 71 electrons arranged in shells as 2, 8, 18, 32, 9, 2.
What is the atomic mass of Lutetium?
The standard atomic weight of Lutetium is 174.97 u, so one mole of Lutetium atoms has a mass of about 174.97 g.
Is Lutetium a metal?
Yes. Lutetium is a lanthanide.
Explore nearby elements
More lanthanides: Terbium, Dysprosium, Holmium, Erbium, Thulium, Ytterbium. See all elements on the periodic table.