Transuranium element

The transuranium elements are the elements with a higher atomic number than uranium (greater than 92).

Properties

All transuranic elements are radioactive with half -lives ranging from some 10 million years (rarely, eg, plutonium -244 ) for minutes up to fractions of a second (common). Some of the lighter isotopes of transuranic elements neptunium and curium have half-lives of a few million years, millennia or centuries. They are created in nuclear reactors and make a part of the long-lived radioactive waste from.

After uranium with an atomic number of 92, the number of Transuranium Elements begins with the neptunium ( element 93). In addition to the major for the fission element plutonium (94 ) also include americium (95 ), Curium (96 ), berkelium (97 ), californium (98), einsteinium (99 ), fermium (100) Mendelevium (101 ), nobelium ( 102) and Lawrencium (103 ) and all other heavier elements ( transactinides ) to the transuranic elements.

The transuranic elements here mentioned by name were made in the working group of Glenn T. Seaborg and characterized; Seaborg was awarded the 1951 Nobel Prize in Chemistry.

Up to and including element 103, the Lawrenciums, they belong together with thorium (90 ), protactinium (91) and uranium ( 92) to the group of actinides.

Occurrence and extraction

Because of the geologically short half-lives are transuranic elements in nature or only in trace caused by neutron capture and subsequent beta decay of uranium, for example:

The only exception is the plutonium 244Pu, which dates back to the origins of the solar system.

Transuranic elements can be technically produced from uranium or other elements with high atomic number. For this purpose, such nuclei are bombarded with neutrons or other atomic nuclei; thereby occurring nuclear fusion produce transuranic elements.

Original Meaning of the word

Originally transuranic was a shorter name for an artificial super heavy element. The occurring in the tiniest traces of plutonium -244 from the time when the solar system was only in 1971, long after the coining of the term " transuranic " discovered. In the original meaning should therefore give speak of "trans - plutonium elements " today.