Write about Curium atom.

   

 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 and Pierre Curie, both 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 1947.  Most curium is produced by bombarding uranium of 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 Alpha particles, and and the heat released in this process can serve as a heat source in radioisotope thermoelectric generators, but this application is hindered by the scarcity and high cost of curium isotopes.  Curium is used in production of heavier actinides and of the 238Pu radionuclide for power sources in artificial pacemakers and RTGs for spacecraft.  It served as the Alpha source in the aplha particle X-ray spectrometers installed on several space probes, including the Sojourner, Spirit, Opportunity and Curiosity Mars rovers and the Philae lander on comet 67P/churyumov-Gerasimenko, to analyze the composition and structure of the surface.