Page 1 Contents: #21 Sc, #31 Ga, #32 Ge, #39 Y, #44 Ru, #63 Eu, #65 Tb, #67 Ho, #68 Er, #69 Tm, #70 Yb, #71 Lu, #84 Po
Page 2 Contents: #43 Ma, #72 Hf, #75 Re, #87 Fr, #95 Am, #97 Bk, #98 Cf, #105 Db, #108 Hs, #110 Ds,
|Portrait by permission
U. of Turku
In 1787 a student of the Swedish chemist Berzelius, Carl Arrhenius, found in the feldspar quarry at Ytterby near Stockholm a dense black rock which he called ytterite. Johan Gadolin (1760-1852 portrait at left and later on the coin), professor of chemistry at Åbo, Finland, analyzed the rock in 1794. Gadolin, the foremost Finnish chemist of his day, found 38% of the rock to be a new earth which he called yttria. In the decades after Antoine Lavoisier developed the new chemistry built on the concept that earths (compounds of elements, usually oxides) could be reduced to their elements, the discovery of a new earth (with name ending in "a") was regarded as equivalent to discovering the element within. Thus the element reducible from the earth yttria would be Yttrium: (Y = #39). Gadolin's textbook published in 1798 was the first in Swedish to present Lavoisier's new chemistry. Later the dense black rock was renamed gadolinite in his honor. Other chemists studied ytterite/gadolinite and found additional elements, one of which was named Gadolinium. (Read Sir Johan Gadolin of Turku: The Grandfather of Gadolinium by Peter and Kirsti Dean. View images of Gadolin they have collected.)
Jöns Jacob Berzelius;(1779-1848) and G.W. Osann, professor of chemistry at Dorpat on Russia´s Baltic coast, both examined residues of Platinum ore from the Ural Mountains (mid-continent Russia). After dissolving the ore in aqua regia in 1827, Berzelius found nothing new, but Osann believed there was evidence for three new elements, one he called Ruthenium (Ru = #44) (Latin) for Russia.
In 1839 Carl Gustav Mosander, (1797-1858 at left) an assistant of Berzelius, found still another earth in gadolinite which he called lanthana meaning hidden. Believing there were additional constituents, Mosander treated lanthana with dilute nitric acid and in 1841 extracted a rose-colored earth he believed contained a second new element Didymium, an inseparable twin brother of Lanthanum. Continuing, he showed in 1843 that yttria contains at least three other earths, a colorless oxide which he left named yttria, a yellow earth, erbia, reducing to Erbium (Er = #68), and a rose-colored terbia which would reduce to element Terbium (Tb = #65). The names of erbia and terbia since were interchanged.
Karl Karlovich Klaus, (1796-1864 photo right) started an investigation in 1840 to settle the discrepancy between Berzelius and Osann about Ruthenium. He had been largely self taught since dropping out of school to become a pharmacy apprentice at age 14. Originally from Dorpat, he spent much of his life investigating the flora and fauna of the steppes in eastern Russia. He wrote a large book on the region between the Urals and the Volga. Now a full professor at Kazan, he investigated Platinum ore residues and published a 188 page report in 1844. He sent samples to Berzelius in 1845 resulting in Berzelius´ announcement that Ruthenium is indeed a new element. In 1863 the Russian government sent Klaus to western Europe to further study Platinum where he was honored wherever he went.
Jean-Charles Galissard de Marignac (1817-1894), a descendant of a Huguenot family that had fled France a century earlier, was born in Geneva, studied at the École Polytechnique at Paris and the School of Mines, and travelled through Scandinavia and Germany. After working in a porcelain works, he was professor of chemistry at the Geneva Academy. He made many precise determinations of atomic weights to test Prout's hypothesis that atomic weights were exact multiples of Hydrogen's. He began a study of the rare earths when he was 23, and in 1878 he decomposed erbium nitrate with heat, and extracted with water two oxides, the red erbia, and a new colorless one which he named, ytterbia reducible to element Ytterbium (Yb = #70). Thus the names for four elements, Yttrium, Ytterbium, Erbium, and Terbium, were all derived from the village of Ytterby, the source of the dense black rock, gadolinite. (See map.)
Per Theodor Cleve (1840-1905 photo right) the 13th child of a Stockholm merchant, graduated from the University of Upsala where, after further study in Paris, he became a professor. Working with some erbia from which all the ytterbia and scandia have been removed, he noted the atomic weight of Erbium was not constant. He resolved the earth into three constituents: erbia, holmia, and thulia. He derived the name Holmium (Ho = #67) for his native city, and Thulium (Tm = #69) from Thule, an old name for Scandinavia. (See map.)
Following earlier attempts at classification of elements by Johann Wolfgang Döbereiner (1780-1849) (see his triads of elements),f in March 1869 Dmitri Mendeleev published a paper onMendeleev had predicted the existence of element #21 which he called eka-Boron. Upsala professor Lars Fredrik Nilson (1840-1899), a disciple of Berzelius, undertook a study of the minerals euxenite and gadolinite in an effort (that failed) to show that rare earth elements and their compounds neatly fit the periodic law. In 1879 he obtained pure ytterbia and a new element that he found matched Mendeleev´s eka-Boron. (Read Nilson's account.) He called the new element Scandium (Sc = #21), (Latin) for Scandinavia, in honor of his homeland. (See map.)The Relation of Properties to Atomic Weights of the Elementswhich suggested a periodic table. (See Mendeleev's table).f He claimed that inconsistent atomic weights were errors, and predicted detailed properties for several missing elements. In December 1869, Lothar Meyer independently proposed a similar table without predictions. (See Meyer's chart).f Previously each new discovery was an unexpected event. There was no way to predict elements or foretell their physical or chemical properties. Within 15 years, three elements predicted by Mendeleev were discovered, named after their countries of discovery, and found to precisely match predicted properties.
Paul Émile (dit François) Lecoq de Boisbaudran (1838-1912) was one of the founders of spectroscopy (with Bunsen and Kirchhoff of the University of Heidelberg). A 15 year study of spectra lead Boisbaudran to find that several metals in the same family emit spectral lines that repeat the same general arrangement. In an attempt to verify the pattern for the Aluminum family and find the missing family member predicted by his own law of spectra, he investigated Zinc ore. Depositing Zinc and examining its spectra with a Hydrogen-Oxygen flame, Boisbaudran detected two new spectral lines not seen with a Bunsen burner. He wrote:
Between 3 and 4 in the evening of August 27, 1875 I found indications of the probable existence of a new elementary body... chiefly of a violet ray, narrow, readily visible, and situated at about 417 on the scale of wavelengths. I perceived also a very faint ray at 404. This metal he named Gallium (Ga = #31), (Latin) for France. A month later he proved that Gallium is a true element. In November Mendeleev stated that he believed Gallium to be identical with his predicted element 31, called eka-Aluminum. This was confirmed. (Read Boisbaudran's account.)f Boisbaudran´s subsequent spectral analyses of rare earths led to the discovery of Samarium and Dysprosium.
Predicted as a missing element by Mendeleev in 1871, element #32 was found in 1886 by Clemens Alexander Winkler(1838-1904). Born in Freiberg to the son of a chemist who operated the smalt works in Zschopenthal, Germany, Winkler loved to understand Nature but not collect it. When he entered the Freiberg School of Mines at age 19, he already knew more analytical chemistry than was taught there! He developed equipment and procedures, and produced Nickel and Cobalt commercially. 16 years after beginning his studies there, he was appointed professor at Freiberg. G.D. Hinrichs said,
The perfection of the analytical work of Winkler astonished me till I found the name of his father in the list of special students of Berzelius. When a new ore called argyrodite containing Silver, Sulfur and Mercury was discovered at a nearby mine in 1885, Winker was asked to do a quantitative analysis. When the analysis consistently came out 7% low, he spent four months finding a sulfide that was soluble in water and dilute acids but quite insoluble in concentrated acids. (Read Winkler's account.)f He called the new element Germanium (Ge = #32) after its country of discovery. By 1897 he had obtained convincing proof that Germanium is the eka-Silicon predicted by Mendeleev.
Eugène-Anatole Demarçay (1852-1904) was born in Paris, and studied at the Lycée condorcet, in England, and the École Polytechnique. His study of terpenes and ethers helped the perfume industry. He lost an eye in a explosion while studying nitrogen sulfides. He continued vacuum studies of volatility and low temperatures followed by high temperature spark spectra. The high temperatures sparks from Platinum electrodes produced bright lines useful for the study of rare earths. In 1901 his elaborate separations of samarium magnesium nitrate resulted in discovery spectral lines for an earth which he called Europium (Eu = #63) after the Continent. Since he could read a complex spectrum
like an open book, he was frequently asked to verify new elements and did so for Curies´ Radium.
Element #84 was discovered in 1898 by Marie and Pierre Curie in Paris. Marie, a chemist, became interested in the cause of radiation that Henri Becquerel had recently discovered coming from the ore pitchblende. The Curies used a sensitive electroscope created by Pierre and his brother to trace the radioactive material through numerous separations. Eventually they isolated two new elements which they named Polonium (Po = #84) and Radium. Marie was born and raised in Warsaw. Poland was ruled by the Czar of Russia who attempted to extinguish the Polish language and culture. Naming the element after her homeland helped her underground efforts to preserve the culture. (Read Curies account.)f
|introduction||alchemy||planets||other celestial objects||color||other properties||myths||people||minerals||ore mines||combination names|
|to site menu||Introduction to
Development of Periodic Chart
|18th Century vocabulary,
& index of people
|created 1 January 2001, amplified 19 Feburary
latest revision 16 June 2007
|by D Trapp|