Ytterbium is a chemical element with the atomic number 70 in the periodic table. It’s the 44th most plentiful metal found in Earth’s crust. Being a member of the lanthanides family of elements, this rare-earth metal is a divalent substance with a high energy-level atomic structure that resembles the one of the element strontium. Element 70 occurs in three structural forms and has few practical uses.
Chemical and Physical Properties of Ytterbium
The symbol in the periodic table of elements: Yb
Atomic number: 70
Atomic weight (mass): 173.04 g.mol-1
Group number: Lanthanides
Period: 6 (f-block)
Color: Bright silvery luster
Physical state: Solid at room temperature
Half-life: From 250 milliseconds to 32.026(5) days
Electronegativity according to Pauling: 1.1
Density: 7 (6.90) g.cm-3 at 20°C
Melting point: 824°C, 1515°F, 1097 K
Boiling point: 1196°C, 2185°F, 1469 K
Van der Waals radius: Unknown
Ionic radius: Unknown
Most characteristic isotope: 172Yb, 173Yb, 174Yb
Electronic shell: [Xe] 4f146s2
The energy of the first ionization: 602.4 kJ.mol-1
The energy of the second ionization: 1172.3 kJ.mol-1
The energy of the third ionization: 2472.3 kJ.mol-1
Discovery date: In 1878 by Jean C.G. de Marignac
With the periodic table symbol Yb, atomic number 70, atomic mass of 173.04 g.mol-1, and electron configuration [Xe] 4f146s2, ytterbium is a soft, ductile, and malleable metal with a bright, silvery-white appearance. It reaches its boiling point at 1196°C, 2185°F, 1469 K, while the melting point is achieved at 824°C, 1515°F, 1097 K. This member of the lanthanides family of elements has an electronegativity of 1.1 according to Pauling, whereas the atomic radius of ytterbium according to van der Waals is unknown.
Classified as a rare-earth metal, ytterbium tarnishes upon exposure to air. The oxidation of this chemical element in a reaction with O2 gives ytterbium strong anticorrosive properties. Ytterbium also forms strong reactions with mineral acids.
How Was Ytterbium Discovered?
Jean Charles Galissard de Marignac (1817 – 1894) was a Swiss chemist who dedicated his work to the study of rare-earth elements. By performing one of his experimental trials, he even discovered one of these elusive substances – the ytterbium.
To begin with, the story on the discovery of all rare-earth elements begins when the Swedish scientist Carl Gustaf Mosander succeeded in separating the gadolinite mineral into three new substances. He conveniently named them: yttria, erbia, and terbia. As rare-earth elements always occur along each other, his fellow scientists dedicated their work to a more detailed analysis of the rare minerals in the quest of discovering a new element.
The discovery of ytterbium happened in 1878 when de Marignac attempted heating of erbium nitrate to the point it decomposed. In the residue left from this chemical reaction, Jean de Marignac observed two substances – erbia and a white powder that was previously undetected by any of his fellow scientists. The Swiss chemist named the newly discovered substance ytterbium oxide (ytterbia).
Ytterbium metal was prepared by the scientists Klemm and Bonner in 1937. To achieve this scientific feat, these two scientists exposed ytterbium chloride and potassium to heat and produced the metal form of element 70.
How Did Ytterbium Get Its Name?
Just like the elements yttrium, terbium, and erbium, element 70 was named ‘ytterbium’ after the Swedish village Ytterby. This village in Sweden is famous in the world of chemistry as a location rich in mineral sources for rare-earth elements.
Where Can You Find Ytterbium?
Ytterbium is a naturally occurring rare-earth metal. It’s always found along other rare-earth elements in minerals, such as monazite, gadolinite, euxenite, and xenotime.
For commercial purposes, ytterbium is mainly extracted from monazite sand by the ion exchange process, a reaction with lanthanum metal, or a chemical reaction triggered between potassium and ytterbium trichloride. The largest mines of ytterbium ores are located in Australia, the United States, Sri Lanka, India, Brazil, and China.
Ytterbium in Everyday Life
Despite having limited practical use, ytterbium is considered as one of the most important chemicals applied in processes that are highly beneficial for humanity and our safety:
- One of the most significant uses of ytterbium is in stress gauges where it supports the monitoring of ground deformations triggered by earthquakes or underground explosions;
- The radioactive isotope 160Yb is used as a radiation source in the portable x-ray machines that operate without the need for electricity;
- Ytterbium metal is applied to the stainless steel in order to improve the mechanical properties of this alloy, such as the strength and the grain refinement;
- In fiber optic cables, yttrium is used as a doping agent which amplifies the signals that travel back and forth.
How Dangerous Is Ytterbium?
While the pure, elemental form of ytterbium is classified as a moderately toxic substance, the ytterbium compounds are highly toxic and must be kept in tightly closed containers. Upon exposure to ytterbium metal dust, mild irritations of the eyes, skin, and lungs may occur.
Environmental Effects of Ytterbium
Element 70 has no known biological role. Ytterbium dust is considered to be highly flammable and may pose an explosion and fire hazard.
Isotopes of Ytterbium
There are 34 isotopes of ytterbium. Among them, twenty-seven of the ytterbium forms are observed as radioactive. Elemental ytterbium (70Yb) is composed of seven stable isotopes with atomic mass ranging from 168Yb to 176Yb:
- 168Yb (0.1%);
- 170Yb (3.0%);
- 171Yb (14.3%);
- 172Yb (21.8%);
- 173Yb (16.1%);
- 174Yb (31.8%);
- 176Yb (12.8%).
With an abundance of 31.83%, ytterbium-174 is the most abundant naturally occurring form of element 70. Ytterbium-169 is the longest living form of element 70, with a half-life of 32.018 days.
The primary decay mode before the most abundant stable isotope (174Yb) is electron capture that results in isotopes of thulium as decay products. In addition, the primary decay mode after the most abundant isotope of ytterbium is beta emission and it produces isotopes of lutetium.
|Z||N||Isotopic mass (Da)
[n 2][n 3]
|Natural abundance (mole fraction)|
|Excitation energy[n 4]||Normal proportion||Range of variation|
|149Yb||70||79||148.96404(54)#||0.7(2) s||β+||149Tm||(1/2+, 3/2+)|
|150Yb||70||80||149.95842(43)#||700# ms [>200 ns]||β+||150Tm||0+|
|β+, p (rare)||150Er|
|β+, p (rare)||151Er|
|153Yb||70||83||152.94948(21)#||4.2(2) s||α (50%)||149Er||7/2−#|
|β+, p (.008%)||152Er|
|154Yb||70||84||153.946394(19)||0.409(2) s||α (92.8%)||150Er||0+|
|155Yb||70||85||154.945782(18)||1.793(19) s||α (89%)||151Er||(7/2−)|
|156Yb||70||86||155.942818(12)||26.1(7) s||β+ (90%)||156Tm||0+|
|157Yb||70||87||156.942628(11)||38.6(10) s||β+ (99.5%)||157Tm||7/2−|
|158Yb||70||88||157.939866(9)||1.49(13) min||β+ (99.99%)||158Tm||0+|
|168Yb||70||98||167.933897(5)||Observationally Stable[n 7]||0+||0.0013(1)|
|170Yb||70||100||169.9347618(26)||Observationally Stable[n 8]||0+||0.0304(15)|
|171Yb||70||101||170.9363258(26)||Observationally Stable[n 9]||1/2−||0.1428(57)|
|172Yb||70||102||171.9363815(26)||Observationally Stable[n 10]||0+||0.2183(67)|
|173Yb||70||103||172.9382108(26)||Observationally Stable[n 11]||5/2−||0.1613(27)|
|174Yb||70||104||173.9388621(26)||Observationally Stable[n 12]||0+||0.3183(92)|
|176Yb||70||106||175.9425717(28)||Observationally Stable[n 13]||0+||0.1276(41)|
List of Ytterbium Compounds
Ytterbium occurs in exists in three allotropic forms:
- The close-packed hexagonal α-phase (below 7°C/45°F/280.15K);
- The face-centered cubic β-phase (at room temperature);
- The body-centered cubic γ-phase (at 763°C/1.405°F/1036.15K).
This chemical element has a relatively stable electron configuration, and typically adopts the oxidation state of +2. In the +3 oxidation state, ytterbium forms a series of white salts including trisulfate and trinitrate. Like the element europium, ytterbium has two valence electrons in its outer shell.
Even though ytterbium does not form many compounds, the following list presents the most common ones:
- Ytterbium(III) Chloride Hexahydrate
- Ytterbium Nitrate
- Ytterbium Sulfate
- Ytterbium(III) Oxide
- Ytterbium(III) Fluoride
- Ytterbium(II) Iodide
- Ytterbium(II) Silicide
- Ytterbium Hydroxide
- Ytterbium(III) Iodide
- Ytterbium(II) Telluride
- Ytterbium(III) Chloride
- Ytterbium Acetate
- Ytterbium(III) Bromide
- Ytterbium(II) Selenide
- Ytterbium(II) Fluoride
- Ytterbium Oxalate
- Ytterbium(II) Bromide
- Ytterbium(III) Sulfide
- Copper Ytterbium Oxide
- Ytterbium Carbonate
- Ytterbium(III) Selenide
- Ytterbium(III) Oxalate Hexahydrate
- Ytterbium Dichromate
5 Interesting Facts and Explanations
- Ytterbium is the penultimate chemical substance classified in the lanthanide series of elements in the periodic table that include lutetium (Lu), europium (Eu), samarium (Sm), cerium (Ce), terbium (Tb), lanthanum (La), and erbium (Er).
- A. Daane, David Dennison, and Frank Spedding succeeded in isolating the pure ytterbium metal in 1953, at the Ames Laboratory, Iowa, United States.
- Several decades after the discovery of ytterbium, in 1907, the French chemist Georges Urbain conducted several series of fractional crystallizations of ytterbium nitrate from a nitric acid solution. Urbain managed to produce two rare-earth oxides: neoytterbia and lutecia. The first one was de Marignac’s ytterbium, while the other one was a new element that he labeled as lutetium.
- Generally, the chemical properties of the rare-earth elements are very similar, which makes them hard to distinguish in mineral ore. Ion exchange and solvent extraction techniques are typically used for the extraction of rare-earth elements from mineral ores. This is why these chemical elements are both rare and expensive.
- Ytterbium has the lowest magnetic susceptibility of all rare-earth metals.