Ytterbium
Element 70 · Lanthanide
Ytterbium is a soft, malleable lanthanide that tarnishes slowly in air. Its full 4f shell makes the +2 state accessible, so ytterbium(II) compounds are known alongside the usual +3 ones. It has the lowest density and melting point of the late lanthanides.
It shines in precision technology: ytterbium-doped fibers make efficient high-power lasers for cutting and welding, and ytterbium atoms tick inside optical lattice clocks — the most accurate timekeepers ever built. It also gauges mechanical stress in specialized sensors.
Key facts
| Atomic number | 70 |
|---|---|
| Atomic weight | 173.05 |
| Category | Lanthanide |
| Group / Period | — / 6 |
| Block | f |
| Electron configuration | 1s2 2s2 2p6 3s2 3p6 4s2 3d10 4p6 5s2 4d10 5p6 6s2 4f14 |
| Common oxidation states | +3, +2 |
| State at STP | Solid |
| Electronegativity | 1.10 |
| Density | 6.90 g/cm³ |
| Melting point | 824 °C |
| Boiling point | 1196 °C |
Occurrence
Ytterbium is found in monazite and xenotime, recovered during processing of the more abundant rare earth metals.
Applications
High-power fiber lasers
Optical lattice atomic clocks
Stress and pressure gauges
Stainless steel additive
Common compounds
- ytterbium oxide
- ytterbium fluoride
Ytterbium atomic clocks are so precise they would lose less than a second over the age of the universe — redefining how we measure time itself.
Data source: IUPAC standard atomic weights 2021