What is Ytterbium

Ytterbium (pronunciation: i-TUR-bee-em) ^[2] is a malleable, ductile, bright silvery metal ^[3] that belongs to the group of lanthanides and is represented by the chemical symbol Yb ^[1]. 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 ^[1]. 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 ^[1].

History

Origin of its Name: It is named after Ytterby, a town in Sweden where the element was first found ^[1].

Who discovered it: Jean Charles Galissard de Marignac, a Swiss chemist, is known for its discovery ^[1].

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 ^[1]. 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 ^[1].

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 ^[5].

Ytterbium Identification
Atomic number	70 [1]
CAS number	7440-64-4 [1]
Position in the periodic table	Group	Period	Block
	Lanthanides [1]	6 [1]	f [1]

Properties and Characteristics of Ytterbium

Atomic Data of Ytterbium (Element 70)

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 ^[5].
• Ytterbium-doped fiber amplifiers in tunable lasers are used for marking and engraving ^[5].
• 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 ^[5].

Possible Health Effects

Ytterbium is considered slightly toxic ^[1], and its compounds can cause skin and eye irritations. Metallic ytterbium dust catches fire spontaneously, and the fumes are harmful to human health ^[9].

Interesting Facts

• The element 70 is sometimes represented by an image based on ancient rock art found in Sweden ^[1], 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 ^[10].

Cost of Ytterbium

While 100 grams of pure ytterbium cost around  $1,400, the same amount of the element in bulk costs around  $550 ^[11].

References
1. http://www.rsc.org/periodic-table/element/70/ytterbium
2. https://education.jlab.org/itselemental/ele070.html
3. https://www.livescience.com/38423-ytterbium.html
4. https://www.webelements.com/ytterbium/isotopes.html
5. https://www.chemicool.com/elements/ytterbium.html
6. https://www.webelements.com/ytterbium/physics.html
7. https://chemglobe.org/ptoe/_/70.php
8. http://chemistry-reference.com/q_elements.asp?Symbol=Yb&language=en
9. http://www.elementsdatabase.com/Ytterbium-Yb-70-element/
10. https://www.nist.gov/news-events/news/2016/11/nist-debuts-dual-atomic-clock-and-new-stability-record
11. http://hobart.k12.in.us/ksms/PeriodicTable/ytterbium.htm