Ekeberg

Gr. Tantalos, mythological character, father of Niobe) Discovered in 1802 by Ekeberg, but many chemists thought niobium and tantalum were identical elements until Rowe in 1844, and Marignac, in 1866, showed that niobic and tantalic acids were two different acids. The early investigators only isolated the impure metal. The first relatively pure ductile tantalum was produced by von Bolton in 1903. Tantalum occurs principally in the mineral columbite-tantalite. 

Tantalum [7440-25-7] atomic number 73, is the heaviest element in Group 5 (VA) of the Periodic Table. This tough, ductile, silvery gray metal has an atomic weight of 180.948 amu. The element was discovered by A. K. Ekeberg in 1802 in minerals taken from Kimito, Finland, and Ytterby, Sweden (1). 

In 1794 the Finnish chemist J. Gadolin, while examining a mineral that had recently been discovered in a quarry at Ytterby, near Stockholm, isolated what he thought was a new oxide (or earth ) which A. G. Ekeberg in 1797 named yttria. In fact it was a mixture of a number of metal oxides from which yttrium oxide was separated by C. G. Mosander in 1843. This is actually part of the fascinating story of the rare earths to which we shall return in Chapter 30. The first sample of yttrium metal, albeit very impure, was obtained by F. Wohler in 1828 by the reduction of the trichloride by potassium. 

In the same year that del Rio found his erythronium, C. Hatchett examined a mineral which had been sent to England from Massachusetts and had lain in the British Museum since 1753. From it he isolated the oxide of a new element which he named columbium, and the mineral columbite, in honour of its country of origin. Meanwhile in Sweden A. G. Ekeberg was studying some Finnish minerals and in 1802 claimed to have identified a new element which he named tantalum because of the difficulty he had had in dissolving the mineral in acids. It was subsequently thought that the two elements were one and the same, and this view persisted until at least 1844 when H. Rose examined a columbite sample and showed that two distinct elements were involved. 

One was Ekeberg s tantalum and the other he called niobium (Niobe was the daughter of Tantalus). Despite the chronological precedence of the name columbium, lUPAC adopted niobium in 1950, though columbium is still sometimes used in US industry. Impure niobium metal was first isolated by C. W. Blomstrand in 1866 by the reduction of the chloride with hydrogen, but the first pure samples of metallic niobium and tantalum were not prepared until 1907 when W. von Bolton reduced the fluorometallates with sodium. 

Anders Gustaf Ekeberg (1767-1813) Heinrich Rose (1795-1864) distinguished tantalum from niobium. 

Tantalum (Ta, [Xe]4/145J36x2), name and symbol after the Greek mythological hero Tantalus. Discovered (1802) by Anders Gustav Ekeberg. 

Tantalum Ta 1802 (Uppsala, Sweden) Anders Ekeberg (Swedish) 150... 

Swedish chemist Anders Gustav Ekeberg Hard anticorrosive metal sometimes substituted for platinum used in electrolytic capacitors to power cell phones and computers. 

Tantalum was discovered by the Swedish chemist Anders Ekeberg in 1802, although for a long time after his discovery many chemists believed tantalum and niobium were the same element. In 1866, Marignac developed a fractional crystallization method for separation of tantalum from niobium. Ekeberg named the element in honor of Tantalus, who was Niobe s father in Greek mythology. 

Hvattum, E. and Ekeberg, D., Study of the collision-induced radical cleavage of flavonoid glycosides using negative electrospray ionization tandem quadrupole mass spectrometry, J. Mass Spectrom., 38, 43, 2003. 

After receiving his early education first at the school in Linkoping and then under his stepfather and under tutors, Berzelius studied medicine at Upsala, and at the age of twenty-two years he received his medical degree. Johan Afzelius, a nephew of Torbem Bergman, was then the professor of chemistry, and A. G. Ekeberg, who discovered tantalum at about the time of Berzelius graduation, was an assistant. 

Since minerals which contain niobium almost invariably contain also the closely related element, tantalum, it is small wonder that chemists at first confused the two elements. The discoverer of tantalum was the Swedish chemist and mineralogist Anders Gustaf Ekeberg. He was born at Stockholm on January 16, 1767, the son of Joseph Erik Ekeberg, a... 

Anders Gustaf Ekeberg, 1767-1813. Swedish chemist, mineralogist, poet, and artist. Professor of Chemistry at Upsala when Berzelius was a student there. The discoverer of tantalum. He was one of the first chemists to investigate yttria. 

Ekeberg suffered throughout his life from physical handicaps. A severe cold in childhood made him partially deaf for the rest of his life, and in 1801, when a flask exploded in his hand, he lost the sight of one eye (9). 

When the royal family visited Upsala in November of that year, an elaborate chemical exposition was held in their honor. A poem of three stanzas, which Ekeberg had composed and written with invisible ink, appeared in blue letters when the King warmed the paper. It began as follows ... 

Ekeberg found the yttrotantalite in the same place as the gadolinite at Ytterby, Sweden. He found that both contained a hitherto unknown metal. Because it had been such a tantalizing task to trace it down, Ekeberg named it tantalum (32). 

Ekeberg s later years were made less fruitful by continued illness. 

The few papers which he published contained the results of the analyses of minerals such as gadolinite, the topaz, and an ore of titanium. In his analysis of the mineral water of Medevi he was assisted by an obscure young student who was destined to bring great glory to the University of Upsala. The discovery of such a student as Berzelius was a far greater honor for Ekeberg than his disclosure of the rather rare element, tantalum. 

Berzelius warmly defended Ekeberg s claim to the discovery of this element. In the autumn of 1814 he wrote to Thomas Thomson objecting to an alteration which had been made in an English translation of one of his memoirs. Berzelius had used the word tantalum., and Thomson had evidently substituted the word columbium, whereupon Berzelius wrote, Without wishing to depreciate the merits of the celebrated Hatchett, it is nevertheless necessary to observe that tantalum and its properties in the metallic as well as in its oxidized condition were not known at all before Mr. Ekeberg. ... 

Berzelius went on to explain the differences between Ekeberg s tantalum oxide and the columbium oxide prepared by Hatchett ... 

Now, then [continued Berzelius], it is clear that the columbic acid of Mr. Hatchett, having been composed of oxide of tantalum and tungstic acid, which communicated to it a part of its specific properties, it is clear, I say, that Mr. Hatchett shares the discovery of tantalum in almost the same manner as MM. Fourcroy and Vauquelin share with Mr. Tennant the honor of having discovered osmium ( Thomson s System, Ed. IV, Vol. 1, p. 200), and I suppose that you will not refuse to render the same justice to the work of the Swede Ekeberg that you have just rendered to the Englishman Tennant. ... 

In his reply to this letter on November 5, Thomson explained that he had known very little about Ekeberg s experiments and that his only reason for changing Berzelius nomenclature had been to make the article more intelligible to English readers. He then added ... 

I regret that it never has been in my power to make experiments on either of these substances (columbite or tantalite). Ekeberg supplied me with a good many specimens, but the ship containing them and all my Swedish collection, which I valued highly, was sunk in the Baltic, and all my property lost. Your fact about the new mineral like columbite [sic] is very interesting. I shall insert what you have told me in the next number of my journal. It is all unknown here (14). 

Biographical account of Mr. Ekeberg, assistant professor of chemistry at... 

Ekeberg, A. G., Of the properties of the earth yttria, compared with those of... 

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