Element Discoveries

Blowing the Theory of How We Smell. David Bradley, Elemental Discoveries, Summer... 

The Development of Modern Chemistry. Harper and Row, New York, 1964, xii + 851 pp. including illustrations, Appendixes, (Discovery of the Elements, Discovery of Natural Radioactive Isotopes, Radioactive Decay Series, Nobel Prize Winners in Chemistry, Physics, and Medicine), and Bibliographic Notes. 

The discovery of the rare earth elements provide a long history of almost two hundred years of trial and error in the claims of element discovery starting before the time of Dalton s theory of the atom and determination of atomic weight values, Mendeleev s periodic table, the advent of optical spectroscopy, Bohr s theory of the electronic structure of atoms and Moseley s x-ray detection method for atomic number determination. The fact that the similarity in the chemical properties of the rare earth elements make them especially difficult to chemically isolate led to a situation where many mixtures of elements were being mistaken for elemental species. As a result, atomic weight values were not nearly as useful because the lack of separation meant that additional elements would still be present within an oxide and lead to inaccurate atomic weight values. Very pure rare earth samples did not become a reality until the mid twentieth century. 

Element Discovery Year Discoverers 1st pure isolation Isolators Named after... 

The second phase of transition element discovery involved those which could readily be released from minerals through heating or reduction by hot charcoal. Again copper in the carbonate mineral malachite, silver in the sulfide mineral argentite and mercury as the sulfide in cinnabar might... 

The names and symbols for elements 111-114 are temporary. Final names will be selected when the elements discoveries are verified. 

Whenever something is started, it will get going easily. This was the case with mistaken element discoveries too. Delafontaine thought he discovered another new element in samarskite, and gave it a name decipium, symbol Dp, expected atomic weight 122. He even predicted its absorption spectral line A 416. This element persisted in books on chemistry for a rather long time, one even meets it here and there in the first years of our century (Delafontaine 1878c). 

The most recent spate of elemental discoveries is ako based on technological developments, involving the production and harnessing of beams of pure atoms or pure elementary particles such as neutrons. These particles can be fired at each other with great precision to achieve nuclear fusion reactions and to thereby create new elements with extremely high atomic numbers. The initiator of this field was the American chemist Glenn Seaborg, who first synthesized plutonium in 1943 and went on to head research teams that were responsible for the synthesk of many more trans-uranium elements. 

The dual discoveries of radioactivity and X-rays made possible the further discovery and identification of several new elements, such as radium and polonium, which needed to be accommodated, and thus provided further tests of the robustness of the periodic system and its ability to adapt to changes. Indeed, while it is the electron that is mainly responsible for the chemical properties of the elements, discoveries connected with the nucleus of the atom nevertheless have had a profound influence on the evolution of the periodic system. The exploration of the nucleus, along with further work on the nature of X-rays and radioactivity, led to the discovery of atomic number and isotopy, two developments that would together resolve many of the lingering uncertainties surrounding Dimitri Mendeleevs periodic system. 

Carl Wilhelm Scheele discovered the tungsten mineral scheelite. He isolated and thoroughly described tungsten oxide, which he called tungsten acid. However, he did not have an adequate furnace in his pharmacy to reduce the oxide to metal. This was done by the two Spanish d Elhuyar brothers who are always named as the discoverers. The history of element discoveries is rather random. 

Today, spectroscopy has an extensive use for qualitative and quantitative analysis of complicated materials and this was so in the history of element discoveries since 1850. 

At the time of the petalite analysis, Arfwedson was 25 years old. Berzelius was 38, and ought not yet to have got tired of fame and honor. I n 1803 he had discovered cerium and in 1817, the year of the lithium discovery, he had found and named the element selenium. It would have been tempting to add the element lithium as further scalp to the collection, at least in the form of shared priority with Arfwedson. It is also quite clear that Berzelius contribution to the element discovery was considerable. In science history Arfwedson alone is stated as discoverer of lithium. This was... 

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