What is Ytterbium
Ytterbium (pronunciation: i-TUR-bee-em)  is a malleable, ductile, bright silvery metal  that belongs to the group of lanthanides and is represented by the chemical symbol Yb . It has seven stable naturally occurring isotopes, out of which 174Yb has the greatest natural abundance (32.03%), while 176Yb is the most long-lived with a half-life period of 1026 years [1, 4].
Where is it Found
Ytterbium, like other lanthanides, is commonly obtained from the mineral monazite and is separated through solvent extraction and ion exchange procedures . The top 3 ytterbium-producing nations in the world are China, Russia, and Malaysia while the top 3 countries with the largest ytterbium reserves include China, CIS Countries, and the USA .
Origin of its Name: It is named after Ytterby, a town in Sweden where the element was first found .
Who discovered it: Jean Charles Galissard de Marignac, a Swiss chemist, is known for its discovery .
When and How was it Discovered
In 1794, the Finnish chemist Johan Gadolin discovered yttrium, a metallic chemical element that the scientists believed was a source of other lanthanoids (rare-earth elements) [1, 2]. In 1843, the Swedish chemist Carl Gustaf Mosander separated yttrium into terbium and erbium . While experimenting with erbium at the University of Geneva in 1878, Charles Marignac was able to isolate ytterbium by heating erbium nitrate, obtaining red erbium oxide and a whitish element that he named ytterbium .
In 1937, Klemm and Bonner heated ytterbium chloride together with potassium to produce a small quantity of impure ytterbium metal [1, 5]. A purer form of ytterbium metal was made in 1953 by David Dennison, A. Daane, and Frank Spedding at the Ames Laboratory in Iowa .
|Atomic number||70 |
|CAS number||7440-64-4 |
|Position in the periodic table||Group||Period||Block|
|Lanthanides ||6 ||f |
Properties and Characteristics of Ytterbium
|Atomic mass||173.045 amu |
|Relative atomic mass||173.045 |
|Color||Silvery-white [1, 5]|
|Melting point/freezing point||824 °C, 1515 °F |
|Boiling point||1196 °C, 2185 °F |
|Density||6.90 g cm-3 |
|State of matter at room temperature (solid/liquid/gas)||Solid [1, 5]|
|– Brinell||343 MPa |
|– Mohs||Unknown |
|– Vickers||206 MPa |
|Electrical conductivity||0.0351X106 S/m |
|Thermal (heat) conductivity||34.9 W/(m K) |
|Specific heat||155 J kg-1 K-1 |
|Bulk modulus||30.5 GPa |
|Shear modulus||9.9 GPa |
|Young’s modulus||23.9 GPa |
|– Temperature (K)||400||600||800||1000||1200||1400||1600||1800||2000||2200||2400|
|– Pressure (Pa)||1.03X 10-9||3.84X 10-3||6.74||–||–||–||–||–||–||–||–|
|Oxidation states||3, 2 |
|Isotopes||Isotope||Mass||Abundance||Half-life||Mode of decay|
Atomic Data of Ytterbium (Element 70)
|Valence electrons||2 |
|– n||4 |
|– ℓ||3 |
|– mℓ||3 |
|– ms||-1/2 |
|Electron configuration (noble gas configuration)||[Xe] 4f146s2 |
|– Number of electrons||70 |
|– Number of neutrons||104 |
|– Number of protons||70 |
|Radius of Atom|
|– Atomic radius||2.26 Å |
|– Covalent radius||1.78 Å |
|Electronegativity (Pauling-scale)||Unknown |
|Electron affinity||-1.93 kJ mol-1 |
|Ionization energy (kJ mol-1)||1st||2nd||3rd||4th||5th||6th||7th||8th|
Uses of Ytterbium
- It can be added to alloys like stainless steel for improving its strength, grain refinement, and other mechanical properties [2, 5].
- Its radioactive isotope 160Yb is used as a source of radiation in portable x-ray imaging equipment .
- Ytterbium-doped fiber amplifiers in tunable lasers are used for marking and engraving .
- Ytterbium compounds are now increasingly used as industrial catalysts in place of other catalysts that are considered to be hazardous and polluting [1, 5].
- Since the electric resistance of ytterbium increases with increase in physical stress, it is used in strain gauges for seismic stress monitoring .
Possible Health Effects
Ytterbium is considered slightly toxic , and its compounds can cause skin and eye irritations. Metallic ytterbium dust catches fire spontaneously, and the fumes are harmful to human health .
- The element 70 is sometimes represented by an image based on ancient rock art found in Sweden , because the element was found in the same country.
- Two atomic clocks, based on ytterbium, were combined by scientists at the NIST (National Institute of Standards and Technology) in 2016 to create the most stable clock in the world .
Cost of Ytterbium
While 100 grams of pure ytterbium cost around $1,400, the same amount of the element in bulk costs around $550 .