Quick reference
| Property | Value |
|---|---|
| Symbol | Yb |
| Atomic number | 70 |
| Atomic weight | 173.045 |
| Group | Lanthanide (rare earth metal) |
| Discovered by | Jean Charles Galissard de Marignac |
| Discovery date | 1878 |
| Name origin | Named after the village of Ytterby, Sweden |
| Density | 6.90 g/cm³ |
| Melting point | 824 °C |
| Boiling point | About 1196 °C |
| Appearance | Soft, bright silvery metal |
Four elements from one village
In 1787, a lieutenant named Carl Axel Arrhenius found an unusual black rock in a quarry near Ytterby, a small village outside Stockholm, Sweden. This mineral, later called gadolinite, turned out to contain several unknown elements.
Over the following century, chemists discovered that minerals from this quarry contained many new rare earth elements. Four elements are named after Ytterby, more than for any other place on Earth:
| Element | Symbol | Atomic number |
|---|---|---|
| Yttrium | Y | 39 |
| Terbium | Tb | 65 |
| Erbium | Er | 68 |
| Ytterbium | Yb | 70 |
Today, a plaque at the old Ytterby mine honours its place in chemistry history.
Discovering ytterbium
In 1878, Swiss chemist Jean Charles Galissard de Marignac heated erbium nitrate and found it contained a second substance. He named it ytterbium. Later, in 1907, scientists discovered that Marignac’s "ytterbium" was itself a mixture, and lutetium was separated from it.
Pure ytterbium metal wasn’t produced until 1953.
Properties
- Ytterbium is soft enough to cut with a knife.
- It’s malleable and ductile (can be hammered and drawn into wire).
- It slowly tarnishes in air and reacts with water and acids.
- Unusually for a metal, its electrical resistance increases a lot under very high pressure.
- Ytterbium dust can be a fire hazard.
Like other lanthanides, ytterbium fills its 4f electron orbitals. With 14 electrons, ytterbium’s 4f shell is completely full, which gives it some unusual properties compared with its neighbours.
Uses of ytterbium
Atomic clocks
Some of the most precise atomic clocks in the world use ytterbium atoms. Scientists trap thousands of ytterbium atoms with lasers and measure their vibrations. These "optical lattice clocks" are so accurate they would drift by less than a second over billions of years.
Such clocks can even detect tiny differences in gravity: a clock lifted just a centimetre higher ticks very slightly faster, as Einstein’s relativity predicts.
Lasers
Ytterbium is used for doping glass fibres to make powerful fibre lasers.
| Use | How |
|---|---|
| Cutting and welding metal | High-power ytterbium fibre lasers |
| Laser marking | Engraving barcodes and logos |
| Medicine | Some surgical and dental lasers |
| Research | Ultra-fast laser pulses |
Other uses
- Improving the strength and grain structure of stainless steel
- Some types of glass and ceramics
- Stress gauges that measure pressure from earthquakes and explosions
- Research in quantum computing, where trapped ytterbium ions can act as qubits
Where it’s found
Ytterbium is found with other rare earths in minerals like monazite, xenotime and gadolinite. It’s separated using complex chemical processes. Most of the world’s supply comes from China.
Common mistakes
- Confusing ytterbium (Yb) and yttrium (Y). They’re different elements, both named after Ytterby.
- Thinking all lanthanides behave identically. Their properties differ in important ways.
Try it yourself
- Find all four Ytterby elements on the periodic table and colour them.
- Research how atomic clocks are used in GPS.
- Make a timeline of the discovery of the Ytterby elements.
Quick recap
- Ytterbium (Yb, atomic number 70) is a soft lanthanide rare earth metal.
- It was discovered by Marignac in 1878.
- It’s one of four elements named after the village of Ytterby, Sweden.
- Ytterbium powers ultra-precise atomic clocks and fibre lasers.
- It also strengthens steel and is used in quantum computing research.