Mosander, Carl Gustaf

Molecular dynamics, 283,285,296, 298 Molten-salt flux synthesis, 392 Monoclinic, 111 Mono-metallofullerenes, 124 Mosander, Carl Gustaf, 6 Mosandrum, 7 Moseley, Henry, 54 Moseley s law, 4... 

Lanthanum (La, [Xe]5 / 6.s 2), name and symbol after the Greek name XavOdvciv (lanthanein, to lie hidden). Discovered (1839) by Carl Gustaf Mosander. Silvery white metal. 

A stone quarry near the town of Ytterby in Sweden produces a large number of rare-earth elements. Carl Gustaf Mosander (1797-1858) discovered several rare-earths, including the rare-earth mineral gadolinite in this quarry in 1843. He was able to separate gadolinite into three separate, but closely related, rare-earth minerals that he named yttria (which was colorless), erbia (yellow color), and terbia (rose-colored). From these minerals, Mosander identified two new rare-earth elements, terbium and erbium. The terbia that was found was really a compound of terbium terbium oxide (Tb O )... 

In the 1800s chemists searched for new elements by fractionating the oxides of rare-earths. Carl Gustaf Mosander s experiments indicated that pure ceria ores were actually contaminated with oxides of lanthanum, a new element. Mosander also fractionated the oxides of yttria into two new elements, erbium and terbium. In 1878 J. Louis Soret (1827—1890) and Marc Delafontaine (1837-1911), through spectroscopic analysis, found evidence of the element holmium, but it was contaminated by the rare-earth dysprosia. Since they could not isolate it and were unable to separate holmium as a pure rare-earth, they did not receive credit for its discovery. 

Carl Gustaf Mosander, a Swedish chemist, successfully separated two rare-earths from a sample of lanthanum found in the mineral gadolinite. He then tried the same procedure with the rare-earth yttria. He was successful in separating this rare-earth into three separate rare-earths with similar names yttia, erbia, and terbia. For the next 50 years scientists confused these three elements because of their similar names and very similar chemical and physical properties. Erbia and terbia were switched around, and for some time the two rare-earths were mixed up. The confusion was settled ostensibly in 1877 when the chemistry profession had the final say in the matter. However, they also got it wrong. What we know today as erbium was originally terbium, and terbium was erbium. 

Swedish chemist Carl Gustaf Mosander Silvery, reactive, malleable first of the rare earth elements, whose added electrons are hidden in their atoms interiors as a compound used in high-intensity lighting. 

Swedish chemist Carl Gustaf Mosander Found in the minerals xenotime and euxerite of which it is an impurity soft and malleable metal has few uses other than in inexpensive glass and jewelry. 

It was one of Berzelius assistants and the curator of the mineral collections of the Stockholm Academy of Sciences, Carl Gustaf Mosander (1797-1858), who demonstrated the complexity of both "yttria" and "ceria." When Mosander heated some "cerium" nitrate in 1839, the salt partly decomposed, and on a treatment with dilute nitric acid, he succeeded in extracting a new earth. He called the new element lanthanum (German Lanthan) and its oxide "lanthana." Mosander retained the old name ceria (Ce) for the insoluble portion of the "ceric" oxide in nitric acid. 

Elemental lanthanum has a ground state (electronic configuration) of [Xe]5d6s. Naturally occurring lanthanum is a mixture of two stable isotopes, La and La. The element was discovered in 1839 by Carl Gustaf Mosander in the form of the lanthanum oxide, at that time called lanthana. The name is derived from the Greek lanthanein ( to fie hidden ), as the element had been overlooked due to its similarity to the earlier discovered cerium. 

Carl Axel Arrhenius found in 1787 in a quarry near Ytterby, Sweden, a new mineral, which he named ytterbite, and made a summary analysis of it. Further, the Finnish chemist Johan Gadolin isolated in 1794 from this mineral an impure new oxide that he named ytterbia. Friedrich Wohler partly purified the metal yttrium in 1828, whereas Carl Gustaf Mosander separated the oxides of yttrium, erbium and terbium in 1843 from a mixture of yttria oxide. 

It was Carl Gustaf Mosander, assistant of Berzelius who, in the twenties of the 19th century, again took up the oxides of the two elements and continued his work imperturbably for over two decades, with the result that the two elements turned into six. 

Fig. 4. Carl Gustaf Mosander (Courtesy Library Karolinska Institutet Stcwkholm).

Carl Gustaf Mosander (1797-1858) - like so many chemists of the age - started his career as a pharmacist s apprentice in Stockholm. Later he entered the school for army surgeons and served for some years in the army as surgeon. Meanwhile he studied at the University of Medicine, and after graduation became an assistant at its department of chemistry headed by Berzelius. In 1832, after Berzelius s retirement, Mosander was appointed professor as successor of Berzelius and held that post until his death. In general, he was reluctant to write papers, most of his results survived in the Jahresberkhte of Berzelius or as printed notes of his lectures (Kopperl 1974). 

English agricultural scientist Sir John Bennett Lawes patents the process of manufacturing superphosphate. Swedish chemist Carl Gustaf Mosander identifies the elements erbium and terbium. 

Discovery Carl Gustaf Mosander in Stockholm discovered the new element, hidden in cerium, in 1839. 

Discovery Carl Gustaf Mosander in Stockholm discovered didymium, the twin , in 1840. Carl Auer von Welsbach in Vienna discovered in 1885 that didymium is composed of two elements. One of them he called praseodymium the green twin , the other neodymium the new twin . 

Discovery Carl Gustaf Mosander in Stockholm in 1842-43 found that Gadolin s yttrium, the first rare earth metal discovered, was composed of three elements. One was allowed to keep the name yttrium, while the two others became terbium and erbium. Thus these new elements also got their names from Ytterby. 

Carl Gustaf Mosander, Lanthanum 1839 Lanthanum was discovered in... 

This laboratory, described with such great insight by Johnston, certainly influenced the development of laboratories and examination techniques in other parts of Europe. The fact that the famous German chemist Friedrich Wohler frequently worked as a visiting scientist in the laboratory also contributed to its influence. Carl Gustaf Mosander s substantial work with rare earths around 1840 was also performed here. This led to the discovery of the elements lanthanum, didymium, erbium and terbium. 

It was Carl Gustaf Mosander (Figure 17.8), from 1836 Berzelius successor as professor of chemistry, who started the great work of separating the almost inseparable. As Berzehus student from 1820 he soon came into his service. He prepared cerium sulfide and let it react with chlorine. Anhydrous cerium chloride CeClj, was formed, from which he prepared metalHc cerium by reduction with potassium metal. This was in about 1825. With all his work with different cerium compounds he began to... 

In 1836, at the age of 57, Berzelius rehred from his professorship and was succeeded by Carl Gustaf Mosander. Berzelius, however, continued with active work almost to his death in 1848. 

A. Lundgren, Carl Gustaf Mosander , Svenskt Biografiskt Lexikon, 25 (1985-87), pp. 739-742. 

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