Curium

Curium is a <a href="/facts/Synthetic_element/azU9Nr1m">synthetic chemical element</a>; it has <a href="/facts/Chemical_symbol/2Fe1VAL0">symbol</a> Cm and <a href="/facts/Atomic_number/bgAr581S">atomic number</a> 96. This <a href="/facts/Transuranium_element/a12PwdAw">transuranic</a> <a href="/facts/Actinide/kHC4lxJV">actinide</a> element was named after eminent scientists <a href="/facts/Marie_Curie/EGjeuJ14">Marie</a> and <a href="/facts/Pierre_Curie/Sbtlw2xj">Pierre Curie</a>, both known for their research on <a href="/facts/Radioactivity/Ya6FVjt4">radioactivity</a>. Curium was first intentionally made by the team of <a href="/facts/Glenn_T._Seaborg/w1a3mume">Glenn T. Seaborg</a>, <a href="/facts/Ralph_A._James/e9SxKjL9">Ralph A. James</a>, and <a href="/facts/Albert_Ghiorso/jP5gHCwp">Albert Ghiorso</a> in 1944, using the <a href="/facts/Cyclotron/Q8APwhWm">cyclotron</a> at <a href="/facts/Lawrence_Berkeley_National_Laboratory/tvjPSwC9">Berkeley</a>. They bombarded the newly discovered element <a href="/facts/Plutonium/4bUw9zH3">plutonium</a> (the isotope <a href="/facts/Plutonium-239/eRobTXos">239Pu</a>) with <a href="/facts/Alpha_particle/dzNMs9WP">alpha particles</a>. This was then sent to the <a href="/facts/Metallurgical_Laboratory/oL5Rf9Lg">Metallurgical Laboratory</a> at <a href="/facts/University_of_Chicago/z6zRMUmV">University of Chicago</a> where a tiny sample of curium was eventually separated and identified. The discovery was kept secret until after the end of <a href="/facts/World_War_II/2efV5L1U">World War II</a>. The news was released to the public in November 1947. Most curium is produced by bombarding <a href="/facts/Uranium/n2sGWBzU">uranium</a> or plutonium with <a href="/facts/Neutron/oRCM1geb">neutrons</a> in <a href="/facts/Nuclear_reactor/8xqjIbge">nuclear reactors</a> – one <a href="/facts/Tonne/gMymLmWv">tonne</a> of spent <a href="/facts/Nuclear_fuel/8RhAomlJ">nuclear fuel</a> contains ~20 grams of curium. 
Curium is a hard, dense, silvery metal with a high melting and boiling point for an actinide. It is <a href="/facts/Paramagnetism/vj1SMbbp">paramagnetic</a> at <a href="/facts/Standard_temperature_and_pressure/JhJv9KFJ">ambient conditions</a>, but becomes <a href="/facts/Antiferromagnetism/aQ124Kh7">antiferromagnetic</a> upon cooling, and other magnetic transitions are also seen in many curium compounds. In compounds, curium usually has <a href="/facts/Valence_(chemistry)/ck7cHByj">valence</a> +3 and sometimes +4; the +3 valence is predominant in solutions. Curium readily oxidizes, and its oxides are a dominant form of this element. It forms strongly <a href="/facts/Fluorescence/qsJVT2qP">fluorescent</a> complexes with various organic compounds. If it gets into the human body, curium accumulates in bones, lungs, and liver, where it promotes <a href="/facts/Cancer/PVW6n1D0">cancer</a>.
All known <a href="/facts/Isotope/KD9B1y6o">isotopes</a> of curium are radioactive and have small <a href="/facts/Critical_mass/BrzhevQR">critical mass</a> for a <a href="/facts/Nuclear_chain_reaction/3l0lHBM4">nuclear chain reaction</a>. The most stable isotope, 247Cm, has a half-life of 15.6 million years; the longest-lived curium isotopes predominantly emit <a href="/facts/Alpha_decay/rCsHNIUE">alpha particles</a>. <a href="/facts/Radioisotope_thermoelectric_generator/Tsjjvp5h">Radioisotope thermoelectric generators</a> can use the heat from this process, but this is hindered by the rarity and high cost of curium. Curium is used in making heavier actinides and the 238Pu <a href="/facts/Radionuclide/5WpCfbdq">radionuclide</a> for power sources in <a href="/facts/Artificial_cardiac_pacemaker/b90Qt8ND">artificial cardiac pacemakers</a> and <a href="/facts/Radioisotope_thermoelectric_generator/Tsjjvp5h">RTGs</a> for spacecraft. It served as the α-source in the <a href="/facts/Alpha_particle_X-ray_spectrometer/ErgoyQW3">alpha particle X-ray spectrometers</a> of several space probes, including the <a href="/facts/Sojourner_(rover)/4aN9KJHz">Sojourner</a>, <a href="/facts/Spirit_(rover)/qNWFPqzj">Spirit</a>, <a href="/facts/Opportunity_(rover)/MEC0VIuy">Opportunity</a>, and <a href="/facts/Curiosity_(rover)/mVLawAfA">Curiosity</a> <a href="/facts/Mars_rover/6ueforXf">Mars rovers</a> and the <a href="/facts/Philae_(spacecraft)/MzUzq8f0">Philae lander</a> on <a href="/facts/Comet/w34utQCd">comet</a> <a href="/facts/67P%2fChuryumov%25E2%2580%2593Gerasimenko/FBdA81uy">67P/Churyumov–Gerasimenko</a>, to analyze the composition and structure of the surface.

Curium open-in-new

Curium