Ytterbium
[Xe] 4f¹⁴ 6s² · 2 · 8 · 18 · 32 · 8 · 2
The lanthanide on whose atoms the most accurate clocks in history are built. Ytterbium optical lattice clocks would drift by a second over more than the age of the universe.
3D model
Bohr model: nucleus and electron shells from the real configuration. Valence electrons are highlighted.
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Atomic properties
- Atomic number
- 70
- Atomic mass
- 173.045 а.е.м.
- Electron configuration
- [Xe] 4f¹⁴ 6s²
- Electrons per shell
- 2 · 8 · 18 · 32 · 8 · 2
- Block
- f-block
- Group
- no data
- Period
- 6
- Electronegativity (Pauling)
- 1.1
- Electronegativity (Allen)
- 1.06
- Atomic radius
- 242 pm
- Covalent radius
- 187 pm
- Van der Waals radius
- 242 pm
- Ionisation energy 1
- 603.4 kJ/mol
- Ionisation energy 2
- 1 174.8 kJ/mol
- Ionisation energy 3
- 2 417 kJ/mol
- Ionisation energy 4
- 4 203 kJ/mol
- Electron affinity
- 50 kJ/mol
- Common oxidation states
- +3
- Oxidation states
- +1, +2, +3
Physical properties
- State at 25 °C
- solid
- Density
- 6.9 g/cm³
- Melting point
- 1 097 K · 823.9 °C
- Boiling point
- 1 469 K · 1 195.9 °C
- Speed of sound
- 1 590 m/s
Thermal properties
- Heat of fusion
- 7.66 kJ/mol
- Heat of vaporisation
- 129 kJ/mol
- Specific heat capacity
- 0.155 J/(g·K)
- Thermal conductivity
- 38.5 W/(m·K)
Mechanical properties
- Young's modulus
- 23.9 GPa
- Shear modulus
- 9.9 GPa
- Bulk modulus
- 30.5 GPa
- Poisson ratio
- 0.21
- Mohs hardness
- no data
- Brinell hardness
- 343 MPa
Electrical and magnetic properties
- Electrical resistivity
- 250 nΩ·m
- Magnetic ordering
- paramagnetic
- Curie point
- no data
- Néel point
- no data
- Superconducting point
- no data
Crystal structure
- Crystal structure
- face-centred cubic (fcc)
- Lattice constants
- a = 548.47 pm
Abundance
- In the crust
- 3.2 mg/kg
- In the ocean
- 8.2·10⁻⁷ mg/L
- In the universe
- 0.2 mg/kg
- In the human body
- 0 mg/kg
Isotopes
| Isotope | Abundance | Half-life | Decay mode |
|---|---|---|---|
| 168Yb | 0.123 % | stable | — |
| 170Yb | 2.982 % | stable | — |
| 171Yb | 14.09 % | stable | — |
| 172Yb | 21.68 % | stable | — |
| 173Yb | 16.103 % | stable | — |
| 174Yb | 32.026 % | stable | — |
| 176Yb | 12.996 % | stable | — |
Seven stable isotopes. Ytterbium-169 serves as a gamma source in brachytherapy.
Discovery
- Year of discovery
- 1878
- Discovered by
- Jean Charles Galissard de Marignac
- Where
- Switzerland
- Origin of the name
- after Ytterby, the village in Sweden
History
Marignac isolated a new earth from erbium in 1878 and named it after the same village of Ytterby. Splitting it into ytterbium and lutetium waited until 1907.
Where it occurs
3.2 mg/kg of the crust. It is recovered from monazite and ion-adsorption clays.
How it is produced
By separating rare-earth concentrates, then reducing the oxide with lanthanum in vacuum.
Role in living things
No biological role.
Safety
Of low toxicity. The metal dust irritates eyes and skin.
Uses
- Optical atomic clocks — record-setting timekeeping accuracy
- Ytterbium fibre lasers for industrial cutting and welding, at over 30 % efficiency
- Pressure sensors: ytterbium's resistance depends strongly on mechanical stress
- Alloying stainless steel for strength
Curiosities
- The ytterbium optical clock is the most accurate measuring instrument humans have ever built.
- Ytterbium fibre lasers have displaced CO₂ lasers in industrial metal cutting.
- Ytterbium is the fourth and last element named after the village of Ytterby.
- Ytterbium's conductivity first rises and then sharply falls under compression — a rare anomaly.