Curium

Both americium and curium are present in solutions mostly in the +3 valence state; whereas americium oxidizes to soluble Am(IV) complexes, curium remains unchanged and can thus be isolated by repeated centrifugation.

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.

Therefore, any primordial curium, that is curium present on the Earth during its formation, should have decayed by now.

They can be prepared by reacting either curium(III) hydride (CmH 3 ) or metallic curium with these elements at elevated temperatures.

Upon short irradiation, this mixture is dominated by curium-246, and then curium-248 begins to accumulate.

A curium compound is then selectively extracted using multi-step chromatographic and centrifugation techniques with an appropriate reagent.

At the same time, they also attempted to synthesize element 103 by bombarding the same curium target used with nitrogen -14 ions.

Between two crystalline forms of curium, the α-Cm is more stable at ambient conditions.

Both Am and Cm are mostly present in solutions in the +3 valence state; whereas curium remains unchanged, americium oxidizes to soluble Am(IV) complexes which can be washed away.

Curium-243 with a ~30 year half-life and good energy yield of ~1.6 W/g could make for a suitable fuel, but it produces significant amounts of harmful gamma and beta radiation from radioactive decay products.

Curium is a hard, dense, silvery metal with a relatively high melting point and boiling point for an actinide.

Curium isotopes are inevitably present in spent nuclear fuel with a concentration of about 20 g/tonne.

Curium is produced artificially, in small quantities for research purposes.

For reasons of military secrecy, this result was published only in 1956. citation Atmospheric curium compounds are poorly soluble in common solvents and mostly adhere to soil particles.

Gmelin Handbook of Inorganic Chemistry, System No. 71, Volume 7a, transuranics, Part A2, p. 289 Therefore, curium can be used in its common oxide form in radioisotope thermoelectric generators like those in spacecraft.

His patent on curium never proved commercially viable because of the element's short half-life, but americium is commonly used in household smoke detectors and thus provided a good source of royalty income to Seaborg in later years.

If consumed, curium is excreted within a few days and only 0.05% is absorbed in the blood.

Initially, curium(III) fluoride was used for this purpose.

More long-lived isotopes of curium ( 245–248 Cm, all α-emitters) are formed as a mixture during neutron irradiation of plutonium or americium.

Np(V) does not bond as readily to soil particles in mildly acidic conditions as its fellow actinides americium and curium by nearly an order of magnitude.