Cleve, Per Teodor

Cleve, Per Teodor (1840-1905) Swedish chemist who worked on the rare earths and decided that the element didymium. 

Holmium Ho 1879 (Uppsala, Sweden) Per Teodor Cleve (Swedish) 295... 

Swedish chemist Per Teodor Cleve Derives from the mineral monazite very scarce and expensive has few commercial applications. 

Tbe erbia left after the removal of ytterbia and scandia was still further resolved by Per Teodor Cleve, f who was bom on February 10,... 

Per Teodor Cleve, 1840—1905. Professor of chemistry at Upsala. Chairman of the Nobel Committee for chemistry. Cleve and Nils Abraham Langlet were independent discoverers of terrestrial helium. Sir William Ramsay s announcement was made before their research was completed. 

Birth of Per Teodor Cleve, the discoverer of thulium, at Stockholm. 

Helium on Earth For the next 30 years, chemists looked for helium on Earth. Then, in 1895, the English physicist Sir William Ramsay (1852-1916) found helium in a mineral of the element uranium. Credit for the earthly discovery of helium is sometimes given to two other scientists also. Swedish chemists Per Teodor Cleve (1840-1905) and Nils Abraham Langlet also discovered helium at about the same time in a mineral called cleveite. 

Holmium was discovered by Swedish chemist Per Teodor Cleve (1840-1905) in 1879. He named the element after his birthplace, Stockholm, Sweden. Holmium occurs with other rare earth elements in minerals such as monazite and gadolinite. ft can now be separated from other rare earth elements somewhat easily. But no major uses have been found for it or its compounds. 

In 1879, Per Teodor Cleve was studying an earth taken from yttria called erbia. Erbia had been regarded as a new element for some time. But Cleve separated erbia into three different parts. He called them erbia, holmia, and thulia. Holmia is the earth from which the element holmium comes. For his work, Cleve is given credit for the discovery of holmium. 

Thulium was given its name in honor of the earliest name for Scandinavia, Thule. The element was discovered and named by Swedish chemist Per Teodor Cleve (1840-1905) in 1879. Cleve made his discovery while studying the mineral erbia. Thulium was one of the many new elements found in a black rock discovered outside the town of Ytterby, Sweden, in 1787. The complete analysis of that rock took more than 100 years. In the process, nine new elements, including thulium, were discovered. 

Swedish chemist Per Teodor Cleve discovers holmium and thulium. 

Fig. 7. Per Teodor Cleve (Courtesy Library University of Uppsala).

Per Teodor Cleve was born in Stockholm in 1840. He studied science at the Uppsala university and started his career as an assistant at this university, in 1874 he was appointed professor of chemistry and held this post until his death. He was the first president, between 1900 and 1905, of the commission which awards the Nobel Prize in chemistry. He began with investigating complex platinum compounds and turned subsequently to rare earth elements. He opposed the ion theory of his contemporary Arrhenius and the novel physico-chemical views of Wilhelm Ostwakl. In the last decade of his life his interest turned towards biology and he was occupied with plankton. He died in Uppsala in 1905 (Boklund 1971). 

The first person to present such tables of comparison for Mendeleev s predictions was Per-Teodor Cleve. 

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