Curium

Curium is a transuranic radioactive chemical element with the symbol Cm and atomic number 96. This element of the actinide series was named after Marie Skłodowska-Curie and her husband Pierre Curie - both were known for their research on radioactivity. Curium was first intentionally produced and identified in July 1944 by the group of Glenn T. Seaborg at the University of California, Berkeley. The discovery was kept secret and only released to the public in November 1945. Most curium is produced by bombarding uranium or plutonium with neutrons in nuclear reactors – one tonne of spent nuclear fuel contains about 20 grams of curium.

Curium is a hard, dense, silvery metal with a relatively high melting point and boiling point for an actinide. Whereas it is paramagnetic at ambient conditions, it becomes antiferromagnetic upon cooling, and other magnetic transitions are also observed for many curium compounds. In compounds, curium usually exhibits valence +3 and sometimes +4, and the +3 valence is predominant in solutions. Curium readily oxidizes, and its oxides are a dominant form of this element. It forms strongly fluorescent complexes with various organic compounds, but there is no evidence of its incorporation into bacteria and archaea. When introduced into the human body, curium accumulates in the bones, lungs and liver, where it promotes cancer.

All known isotopes of curium are radioactive and have a small critical mass for a sustained nuclear chain reaction. They predominantly emit α-particles, and the heat released in this process can potentially produce electricity in radioisotope thermoelectric generators. This application is hindered by the scarcity, high cost and radioactivity of curium isotopes. Curium is used in production of heavier actinides and of the 238Pu radionuclide for power sources in artificial pacemakers. It served as the α-source in the alpha particle X-ray spectrometers installed on the Sojourner, Mars, Mars 96, Athena, Spirit and Opportunity rovers as well as the Mars Science Laboratory to analyze the composition and structure of the rocks on the surface of Mars and the Moon. Such a spectrometer will also be used by the Philae lander of the Rosetta spacecraft to probe the surface of the 67P/Churyumov-Gerasimenko comet.

Read more about Curium:  History, Safety

Other articles related to "curium":

Curium - Safety
... Owing to its high radioactivity, curium and its compounds must be handled in appropriate laboratories under special arrangements ... Whereas curium itself mostly emits α-particles which are absorbed by thin layers of common materials, some of its decay products emit significant fractions of beta and gamma radiation, which require a more ... If consumed, curium is excreted within a few days and only 0.05% is absorbed in the blood ...
Americium - Physical Properties
... to the right of plutonium, to the left of curium, and below the lanthanide europium, with which it shares many similarities in physical and chemical properties ... a density of 12 g/cm3, americium is lighter than both curium (13.52 g/cm3) and plutonium (19.8 g/cm3) but is heavier than europium (5.264 g/cm3)—mostly because of its ... and europium (826 °C), but lower than for curium (1340 °C) ...
Curium Hydroxide
... Curium hydroxide is a radioactive compound first discovered in measurable quantities in 1947 ... It is composed of a single curium atom, and three hydroxide groups ... It was the first curium compound ever isolated ...
Isotope Lists, 73-96 - Curium
... Main article Isotopes of curium Isotope Half-life Spin Parity Mode(s) or Abundance 238Cm 2.4 h 0+ %K=96.16, %α=3.84 239Cm 2.9 h (7/2- ) %K= 100, %α < 0.1 240Cm 27 d 0+ %α > 99.5, %K < 0.5, %SF=3.9E-6 241Cm 32.8 d ...
Americium - History
... Following the lighter neptunium, plutonium, and heavier curium, americium was the fourth transuranium element to be discovered ... Further separation was carried out by ion exchange, yielding a certain isotope of curium ... The separation of curium and americium was so painstaking that those elements were initially called by the Berkeley group as pandemonium (from Greek for ...