Editing Curium (section)

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{{about|the chemical element|the ancient city located in Cyprus|Kourion}}
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'''Curium''' is a [[synthetic element|synthetic chemical element]]; it has [[Chemical symbol|symbol]] '''Cm''' and [[atomic number]] 96. This [[Transuranium element|transuranic]] [[actinide]] element was named after eminent scientists [[Marie Curie|Marie]] and [[Pierre Curie]], both known for their research on [[radioactivity]]. Curium was first intentionally made by the team of [[Glenn T. Seaborg]], [[Ralph A. James]], and [[Albert Ghiorso]] in 1944, using the [[cyclotron]] at [[Lawrence Berkeley National Laboratory|Berkeley]]. They bombarded the newly discovered element [[plutonium]] (the isotope [[plutonium-239|<sup>239</sup>Pu]]) with [[alpha particle]]s. This was then sent to the [[Metallurgical Laboratory]] at [[University of Chicago]] where a tiny sample of curium was eventually separated and identified. The discovery was kept secret until after the end of [[World War II]]. The news was released to the public in November 1947. Most curium is produced by bombarding [[uranium]] or plutonium with [[neutron]]s in [[nuclear reactor]]s – one [[tonne]] of spent [[nuclear fuel]] contains ~20 grams of curium. 

Curium is a hard, dense, silvery metal with a high melting and boiling point for an actinide. It is [[paramagnetism|paramagnetic]] at [[Standard temperature and pressure|ambient conditions]], but becomes [[antiferromagnetism|antiferromagnetic]] upon cooling, and other magnetic transitions are also seen in many curium compounds. In compounds, curium usually has [[valence (chemistry)|valence]] +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 [[fluorescence|fluorescent]] complexes with various organic compounds. If it gets into the human body, curium accumulates in bones, lungs, and liver, where it promotes [[cancer]].

All known [[isotope]]s of curium are radioactive and have small [[critical mass]] for a [[nuclear chain reaction]]. The most stable isotope, <sup>247</sup>Cm, has a half-life of 15.6&nbsp;million years; the longest-lived curium isotopes predominantly emit [[alpha decay|alpha particles]]. [[Radioisotope thermoelectric generator]]s 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 <sup>238</sup>Pu [[radionuclide]] for power sources in [[artificial cardiac pacemaker]]s and [[radioisotope thermoelectric generator|RTG]]s for spacecraft. It served as the α-source in the [[alpha particle X-ray spectrometer]]s of several space probes, including the ''[[Sojourner (rover)|Sojourner]]'', ''[[Spirit (rover)|Spirit]]'', ''[[Opportunity (rover)|Opportunity]]'', and ''[[Curiosity (rover)|Curiosity]]'' [[Mars rover]]s and the [[Philae (spacecraft)|Philae lander]] on [[comet]] [[67P/Churyumov–Gerasimenko]], to analyze the composition and structure of the surface.