A chemical element, Cm, in the actinide series, with an atomic number of 96. Curium does not exist in the terrestrial environment, but may be produced artificially. The chemical properties of curium are so similar to those of the typical rare earths that, if it were not for its radioactivity, it might easily be mistaken for one of these elements. The known isotopes of curium include mass numbers 238–250. The isotope 244Cm is of particular interest because of its potential use as a compact, thermoelectric power source, through conversion to electrical power of the heat generated by nuclear decay. See also: Periodic table
Metallic curium may be produced by the reduction of curium trifluoride with barium vapor. The metal has a silvery luster, tarnishes in air, and has a specific gravity of 13.5. The melting point has been determined as 2444 ± 72°F (1340 ± 40°C). The metal dissolves readily in common mineral acids with the formation of the tripositive ion.
A number of solid compounds of curium have been prepared and their structures determined by x-ray diffraction. These include CmF4, CmF3, CmC3, CmBr3, CmI3, Cm2O3, and CmO2. Isostructural analogs of the compounds of curium are observed in the lanthanide series of elements. See also: Actinide elements; Transuranium elements