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When there is no public data on the element in its pure form, price of a compound is used, per mass of element contained. This implicitly puts the value of compounds' other constituents, and the cost of extraction of the element, at zero. For elements whose radiological properties are important, individual isotopes and isomers are listed. The ...
As of 2003, the two sites produce 0.25 grams and 0.025 grams of 252 Cf per year, respectively. [57] Three californium isotopes with significant half-lives are produced, requiring a total of 15 neutron captures by uranium-238 without nuclear fission or alpha decay occurring during the process.
Transuranic elements are difficult and expensive to produce, and their prices increase rapidly with atomic number. As of 2008, the cost of weapons-grade plutonium was around $4,000/gram, [2] and californium exceeded $60,000,000/gram. [3] Einsteinium is the heaviest element that has been produced in macroscopic quantities. [4]
Its density of 8.84 g/cm 3 is lower than that of californium (15.1 g/cm 3) and is nearly the same as that of holmium (8.79 g/cm 3), despite einsteinium being much heavier per atom than holmium. Einsteinium's melting point (860 °C) is also relatively low – below californium (900 °C), fermium (1527 °C) and holmium (1461 °C).
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Some isotopes undergo spontaneous fission (SF) with emission of neutrons.The most common spontaneous fission source is the isotope californium-252. 252 Cf and all other SF neutron sources are made by irradiating uranium or a transuranic element in a nuclear reactor, where neutrons are absorbed in the starting material and its subsequent reaction products, transmuting the starting material into ...
The heavier isotope 243 Am is produced in much smaller amounts; it is thus more difficult to separate, resulting in a higher cost of the order US$100,000–US$160,000 per gram (US$2,800,000–US$4,500,000/oz). [31] [32] Americium is not synthesized directly from uranium – the most common reactor material – but from the plutonium isotope 239 ...
Its density of 14.78 g/cm 3 lies between those of curium (13.52 g/cm 3) and californium (15.1 g/cm 3), as does its melting point of 986 °C, below that of curium (1340 °C) but higher than that of californium (900 °C). [5] Berkelium is relatively soft and has one of the lowest bulk moduli among the actinides, at about 20 GPa (2 × 10 10 Pa). [6]