Ytterbium
Lanthanide · Period 6 · f-block
The rare earth that ticks inside the world's best atomic clocks
- Atomic mass
- 173.045 u
- State at 25 °C
- Solid
- Electronegativity
- 1.1
- Melting point
- 823.9 °C
- Boiling point
- 1,195.9 °C
- Configuration
- [Xe] 4f14 6s2
Nucleus drawn at reduced count for clarity. Drag to rotate.
Ytterbium, explained
Video lesson in production
Bhavya’s explainer for this element will play here.
Overview
Ytterbium has the configuration [Xe]4f14 6s2. Its 4f shell is completely full, so only the two 6s electrons readily join in metallic bonding. That makes ytterbium behave in some ways like an alkaline earth metal: it is soft, has a lower density and melting point than its neighbours, and dissolves in liquid ammonia to give a blue solution, like calcium does. It forms both Yb3+ and, because of the stable full shell, Yb2+.
Ytterbium's atoms are now among the most precise timekeepers ever built. In an optical lattice clock, thousands of ytterbium atoms are trapped in laser light and probed on an extremely narrow electronic transition. In 2013 such clocks at the US National Institute of Standards and Technology reached a stability of about one part in 10 to the 18th. Ytterbium-doped fibre lasers, which convert electrical power to light efficiently, are workhorses of industrial metal cutting and welding.
Discovery
Swiss chemist Jean Charles Galissard de Marignac separated a new earth from erbia in 1878 and named it ytterbia, after Ytterby, Sweden. In 1907 Georges Urbain in Paris, Carl Auer von Welsbach in Austria and Charles James in the US each showed that Marignac's ytterbia was itself a mixture, splitting off lutetium. Fairly pure ytterbium metal was first made in 1953.
- Where it’s found
- About 3 parts per million of Earth's crust, extracted from monazite, xenotime and ion-adsorption clays.
- What it’s used for
- Optical atomic clocks
- Fibre lasers for cutting and welding
- Stress and pressure gauges
- Stainless steel additive
- Organic synthesis catalysts
- In living things
- No biological role; ytterbium compounds are mildly toxic and can irritate skin and eyes.
- Safety
- Metal dust is flammable and can ignite in air; store bulk metal in sealed containers.
How it compares
Where Ytterbium sits among all 118 elements on the trends that shape the table.
- Electronegativity1.1Pauling
#87 of 100 elements with data
- Ionization energy603kJ/mol
#65 of 104 elements with data
- Atomic radius175pm
#25 of 95 elements with data
- Electron affinity-1.93kJ/mol
#90 of 109 elements with data
- Density6.9g/cm³
#66 of 114 elements with data
- Melting point1,100K
#61 of 110 elements with data
- Density
- 6.9 g/cm³
- Atomic radius
- 175 pm
- Covalent radius
- 170 pm
- Molar heat
- 26.74 J/(mol·K)
- Appearance
- —
- Discovered by
- Jean Charles Galissard de Marignac
Inside the atom
70 electrons arranged in 6 shells: 2 · 8 · 18 · 32 · 8 · 2.
Orbital diagram
1s2 2s2 2p6 3s2 3p6 4s2 3d10 4p6 5s2 4d10 5p6 6s2 4f14 · shorthand [Xe] 4f14 6s2
- 1s2
- 2s2
- 2p6
- 3s2
- 3p6
- 4s2
- 3d10
- 4p6
- 5s2
- 4d10
- 5p6
- 6s2
- 4f14
Each box is an orbital holding up to two electrons of opposite spin. Highlighted subshells hold the valence electrons that decide how Ytterbium bonds.
Ionization energies
Signature reactions
The chemistry Ytterbium is known for.
Redox · Single displacement
Dissolving in hydrochloric acid
Ytterbium dissolves quickly in dilute acid, releasing hydrogen and forming colourless Yb3+ ions. In water the +3 state is the stable one.
Conditions: dilute acid, room temperature
Redox · Combustion
Burning in air
Ytterbium burns to form white ytterbium(III) oxide. This oxide is used in doping laser crystals and fibres.
Conditions: heating in air
Redox · Reduction
Reduction to YbCl2
Hydrogen reduces ytterbium(III) chloride to ytterbium(II) chloride, a reaction that works for very few lanthanides. It reflects the extra stability of Yb2+, with its completely filled 4f shell.
Conditions: heating anhydrous YbCl3 in hydrogen
Where you’ll meet it
Ytterby
Ytterbium is named after this village, whose quarry produced many rare-earth minerals.
Photo: Wikimedia Commons
Atomic clock
Some of the most stable atomic clocks ever built use ytterbium atoms.
Photo: Wikimedia Commons
Optical lattice
Ytterbium atoms are held in crossed laser beams like this while their 'ticks' are measured.
Photo: Wikimedia Commons
Laser cutting
High-power ytterbium-doped fibre lasers are widely used to cut sheet metal.
Photo: Wikimedia Commons
Research
No research on Ytterbium yet
When Bhavya publishes a project that studies Ytterbium, it will be linked here.