Ytterbium

Symbol: Yb Atomic number: 70 Atomic mass: 173.054



Ytterbium has few uses. It can be alloyed with stainless steel to improve some of its mechanical properties and used as a doping agent in fiber optic cable where it can be used as an amplifier. One of ytterbium's isotopes is being considered as a radiation source for portable X-ray machines.
 * Atomic Number:** 70
 * Atomic Weight:** 173.054
 * Melting Point:** 1092 K (819°C or 1506°F)
 * Boiling Point:** 1469 K (1196°C or 2185°F)
 * Density:** 6.90 grams per cubic centimeter
 * Phase at Room Temperature:** Solid
 * Element Classification:** Metal
 * Period Number:** 6
 * Group Number:** none
 * Gr****oup Name:** Lanthanide
 * What's in a name?** Named for the village of Ytterby, Sweden.
 * Say what?** Ytterbium is pronounced as **i-TUR-bee-em**.
 * Estimated Crustal Abundance:** 3.2 milligrams per kilogram
 * Estimated Oceanic Abundance:** 8.2×10-7 milligrams per liter
 * Number of Stable Isotopes:** 6 (View all isotope data)
 * Ionization Energy:** 6.254 eV
 * Oxidation States:** +3, +2

Ytterbium is a soft silvery rare earth element found in the minerals gadolinite, monazite and xenotime.

Ytterbium was discovered in 1878 near the Swedish village Ytterby. That is why it is named Ytterbium.



The mineral gadolinite ((Ce, La, Nd, Y)2FeBe 2 Si 2 O 10 ), discovered in a quarry near the town of Ytterby, Sweden, has been the source of a great number of rare earth elements. In 1843, Carl Gustaf Mosander, a Swedish chemist, was able to separate gadolinite into three materials, which he named yttria, erbia and terbia. As might be expected considering the similarities between their names and properties, scientists soon confused erbia and terbia and, by 1877, had reversed their names. What Mosander called erbia is now called terbia and visa versa. In 1878 Jean Charles Galissard de Marignac, a Swiss chemist, discovered that erbia was itself consisted of two components. One component was named ytterbia by Marignac while the other component retained the name erbia. Marignac believed that ytterbia was a compound of a new element, which he named ytterbium. Other chemists produced and experimented with ytterbium in an attempt to determine some of it's properties. Unfortunately, different scientists obtained different results from the same experiments. While some scientists believed that these inconsistent results were caused by poor procedures or faulty equipment, Georges Urbain, a French chemist, believed that ytterbium wasn't an element at all, but a mixture of two elements. In 1907, Urbain was able to separate ytterbium into two elements. Urbain named one of the elements neoytterbium (new ytterbium) and the other element lutecium. Chemists eventually changed the name neoytterbium back to ytterbium and changed the spelling of lutecium to luteium. Due to his original belief of the composition of ytterbia, Marignac is credited with the discovery of ytterbium. Today, ytterbium is primarily obtained through an ion exchange process from monazite sand ((Ce, La, Th, Nd, Y)PO), a material rich in rare earth elements. Source: []
 * History and Uses:**
 * possible use in improving the grain refinement, strength, and other mechanical properties of stainless steel
 * one isotope apparently used as a radiation source as a substitute for a portable X-ray machine where electricity is unavailable
 * lasers

Examples of where ytterbium can be found is in gadolinite, monazite, and xenotime.

Ytterbium is a soft, __ [|malleable] __ and __ [|ductile] __ __ [|chemical element] __ that displays a bright silvery __ [|luster] __ when in its pure form. It is a __ [|rare earth element] __, and it is readily attacked and dissolved by the strong __ [|mineral acids] __. It __ [|reacts] __ slowly with cold __ [|water] __ and it __ [|oxidizes] __ slowly in air. Natural ytterbium is a mixture of seven stable isotopes which look like this 168Yb, 170Yb, 171Yb, 172Yb, 173Yb, 174Yb, and 176Yb, with 174Yb. It can be mined from China, the United States, Brazil, and India.
 * Physical Properties**

With a __ [|melting point] __ of 824 °C and a __ [|boiling point] __ of 1196 °C, ytterbium has the smallest range of liquid temperature compared to all other metals.

Ytterbium metal tarnishes slowly in air. Finely dispersed ytterbium readily oxidizes in air and under oxygen. Mixtures of powdered ytterbium with __ [|polytetrafluoroethylene] __ or __ [|hexachloroethane] __ burn with a luminous emerald-green flame.
 * Chemical Properties**

Ytterbium is quite __ [|electropositive] __, and it reacts slowly with cold water and quite quickly with hot water to form [|ytterbium hydroxide] : 2 Yb (s) + 6 H 2 O (l) → 2 Yb(OH) 3 (aq) + 3 H 2 (g) Ytterbium reacts with all the __ [|halogens] __: 2 Yb (s) + 3 F 2 (g) → 2 YbF 3 (s) [white]2 Yb (s) + 3 Cl 2 (g) → 2 YbCl 3 (s) [white]2 Yb (s) + 3 Br (g) → 2 YbBr 3 (s) [white]2 Yb (s) + 3 I 2 (g) → 2 YbI 3 (s) [white]

The ytterbium(III) ion absorbs light in the [|near infrared] range of wavelengths, but not in [|visible light], so the mineral [|ytterbia] , Yb2O3, is white in color and the salts of ytterbium are also colorless. Ytterbium dissolves readily in dilute [|sulfuric acid] to form solutions that contain the colorless Yb(III) ions, which exist as a [Yb(OH2)9]3+ complex:

2 Yb (s) + 3 H 2 SO 4 (aq) → 2 Yb 3 + (aq) + 3 SO 4 2− 4  (aq) + 3 H 2 (g)

Chemical compounds
The chemical behavior of ytterbium is similar to that of the rest of the [|lanthanides]. Most ytterbium compounds are found in the +3 oxidation state and its salts in this oxidation state are nearly colorless. Like [|europium], [|samarium] , and [|thulium] , the trihalogens of ytterbium can be reduced by [|hydrogen] or by the addition of the metal to reduce to the dihalogens. The +2 oxidation state reacts in some ways similarly to the [|alkaline earth metal] compounds; for example, Ytterbium(II) oxide (YbO) shows the same structure as [|calcium oxide] (CaO). See also: [|Category:Ytterbium compounds]
 * [|Halides] : [|YbCl2], [|YbBr3] , [|YbCl3] , [|YbF3]
 * [|Oxides] : [|Yb2O3]
 * [|Hydroxide] : ytterbium(III) hydroxide, Yb(OH) 3

Isotopes
Natural ytterbium is composed of seven stable [|isotopes] : 168Yb, 170Yb, 171Yb, 172Yb, 173Yb, 174Yb, and 176Yb, with 174Yb being the most abundant isotope, at 31.8% of the [|natural abundance] ). 27 [|radioisotopes] have been observed, with the most stable ones being Yb-169 with a [|half-life] of 32.0 days, 175Yb with a half-life of 4.18 days, and 166Yb with a half-life of 56.7 hours. All of its remaining [|radioactive] isotopes have half-lives that are less than two hours and the majority of these have half-lives are less than 20 minutes. Ytterbium also has 12 [|meta states], with the most stable being Yb-169m (//t//½ 46 seconds). The isotopes of ytterbium range in [|atomic weight] from 147.9674 [|atomic mass unit] (u) for 148Yb to 180.9562 u for 181Yb. Its primary [|decay mode] at weights lower than the most abundant stable isotope, 174Yb, is [|electron capture], and the primary decay mode above the [|atomic mass number] of 174 is [|beta decay]. The primary [|decay products] at atomic masses lower than 174 are [|thulium] isotopes, and the primary products from above 174 u are element ( [|lutetium] isotopes. Interestingly, in modern [|quantum optics], the different isotopes of ytterbium follow either [|Bose-Einstein statistics] or [|Fermi-Dirac statistics] , leading to significant behavior in [|optical lattices].

Occurrence
Ytterbium is found with other [|rare earth elements] in several rare [|minerals]. It is most often recovered commercially from [|monazite] sand (0.03% ytterbium). The element is also found in [|euxenite] and [|xenotime]. The main mining areas are [|China], the [|United States] , [|Brazil] , [|India] , [|Sri Lanka] , and [|Australia] ; and reserves of ytterbium are estimated as one million [|tonnes]. Ytterbium is normally difficult to separate from other rare earths, but [|ion-exchange] and [|solvent extraction] techniques developed in the mid- to late 20th century have simplified separation. Known [|compounds] of ytterbium are rare and have not yet been well characterized. The abundance of ytterbium in the Earth crust is about 3 mg/kg. The most important current (2008) sources of ytterbium are the ionic adsorption clays of southern China. The "High Yttrium" concentrate derived from some versions of these comprise about two thirds yttria by weight, and 3–4% ytterbia. As an even-numbered lanthanide, in accordance with the [|Oddo-Harkins rule], ytterbium is significantly more abundant than its immediate neighbors, [|thulium] and [|lutetium] , which occur in the same concentrate at levels of about 0.5% each. The world production of ytterbium is only about 50 tonnes per year, reflecting the fact that ytterbium has few commercial applications. [|[3]] Microscopic traces of ytterbium are used as a [|dopant] in the [|ytterbium YAG laser], or [|Yb:YAG laser] , a [|solid-state laser] in which ytterbium is the element that undergoes [|stimulated emission] of [|electromagnetic radiation].

Production
Recovery of ytterbium from ores involves several processes which are common to most rare-earth elements: 1) processing, 2) separation of Yb from other rare earths, 3) preparation of the metal. If the starting ore is [|gadolinite], it is digested with hydrochloric or [|nitric acid] which dissolves the rare-earth metals. The solution is treated with [|sodium oxalate] or [|oxalic acid] to precipitate rare earths as oxalates. For [|euxenite] , ore is processed either by fusion with [|potassium bisulfate] or with [|hydrofluoric acid] . [|Monazite] or [|xenotime] are heated either with sulfuric acid or with caustic soda. Ytterbium is separated from other rare earths either by [|ion exchange] or by reduction with sodium amalgam. In the latter method, a buffered acidic solution of trivalent rare earths is treated with molten sodium mercury alloy, which reduces and dissolves Yb3+. The alloy is treated with hydrochloric acid. The metal is extracted from the solution as oxalate and converted to oxide by heating. The oxide is reduced to metal by heating with [|lanthanum], [|aluminium] , [|cerium] or [|zirconium] in high vacuum. The metal is purified by sublimation and collected over a condensed plate.

Precautions
Although ytterbium is fairly stable chemically, it should be stored in air-tight containers and in an inert atmosphere to protect the metal from air and moisture. All compounds of ytterbium should be treated as highly toxic although initial studies appear to indicate that the danger is minimal. Ytterbium compounds are, however, known to cause irritation to the skin and eye, and some might be [|teratogenic]. Metallic ytterbium dust poses a fire and explosion hazard.