curium Chemische Eigenschaften,Einsatz,Produktion Methoden
Chemische Eigenschaften
silvery white, hard brittle metal; chemistry of trivalent state similar to that of trivalent lanthanides; α-emitter; hexagonal, a=0.3496nm, c=1.1331 nm; enthalpy of vaporization 1340 kJ/mol; ionic radius of Cm+++ is 0.0970nm; discovered in 1944; used in generating thermoelectric power for remote locations and in space; β-Cm is fcc, which is stable at <1340°C [HAW93] [MER06] [KIR78]
Physikalische Eigenschaften
After the discovery of plutonium and before elements 95 and 96 were discovered, theirexistence and properties were predicted. Additionally, chemical and physical properties werepredicted to be homologous (similar) to europium (
63Eu) and gadolinium (
64Gd), locatedin the rare-earth lanthanide series just above americium (
95Am) and curium (
96Cm) on theperiodic table. Once discovered, it was determined that curium is a silvery-white, heavymetal that is chemically more reactive than americium with properties similar to uraniumand plutonium. Its melting point is 1,345°C, its boiling point is ~1,300°C, and its density is13.51g/cm
3.
Isotopes
There are 23 isotopes of curium. All of them are man-made and radioactive.The most stable is curium-247, with a half-life of 1.56×10
+7years (156,600,000 years),which through alpha decay transmutates into plutonium-243.
Origin of Name
Named after Pierre and Marie Curie.
Occurrence
There is no natural curium on Earth. All of its isotopes are man-made and artificiallyproduced through nuclear reactions with other elements. The curium isotope Cm-242 wasfirst produced by bombarding plutonium-239 with helium nuclei (alpha particles), whichcontributed neutrons that changed
94Pu to
96Cm.
Charakteristisch
Curium is a synthetic (not natural) transuranic element of the actinide series. It was determinedthat curium’s major valence and oxidation state was +3, similar to other elements of thisseries. The most stable isotope of curium is curium-247, with a half-life of 1.56×10
+7years.
Verwenden
There are no major commercial uses for curium because of the extremely small amountproduced. In the future, the most important use of curium may be to provide the power forsmall, compact thermoelectric sources of electricity, by generating heat through the nucleardecay of radioisotope curium-241. These small, efficient power sources can be used in individualhomes or remote regions to provide electricity to areas that cannot secure it from othersources. It could also be used as a source of electricity in spacecraft. However, today curium’smain use is for basic scientific laboratory research.
Definition
A highly toxic radioactive
silvery element of the actinoid series
of metals. A transuranic element, it is
not found naturally on Earth but is synthesized
from plutonium. Curium-244 and
curium-242 have been used in thermoelectric
power generators.
Hazard
Curium metal and its compounds are radioactive bone-seeking poisons that attack theskeletal system of humans and animals. Care must be used in handling them.
curium Upstream-Materialien And Downstream Produkte
Upstream-Materialien
Downstream Produkte