The Element Curium
[2023-04-10 18:52:43]
Cur was originally produced by Glenn T. Seaborg, Ralph A. James, Albert Ghiorso of the University of California at Berkeley in 1944. They bombed the strontium isotope α-239 atom, which accelerated alpha particles in a device called a cyclotron. This creates cur - 242 atoms and free neutrons. The half-life of Cur - 242 is about 163 days, it declines from alpha decay to √ - 238, or by spontaneous fission decay.
The most stable isotope of Cur, cur - 247, has a half - life of about 15, 600, 000 years. Collapse to α-243 through alpha collapse
So far only milligram cur has been manufactured so it may be used in the future for radioisotope thermoelectric generators, but currently there is no commercial use. Cur is mainly used in basic scientific research.
Scientists have created several cur compounds. They include ceria (CmO 2), antimony trioxide (Cm 2 O 3), calcium bromide (CmBr 3), calcium chloride (CmCl 3), calcium chloride (CmCl 3), tetrafluoronaphthalene (CmF 4) and Calcium iodide is included. (CmI 3). Like this element, compounds are not currently on the market and are mainly used in basic scientific research.
The synthetic radioactive element cur is a hard, dense metal with a silver white appearance and physical and chemical properties similar to bismuth. Its melting point is 1340 ° C., which is considerably higher than the former transuranium elements ne (637 ° C.), nickel (639 ° C.), and americ (1173 ° C.). In contrast, helium melted at 1312 ° C. The bo boiling point of cur is 3110 ° C. The density is 13.52 g / cm 3, cur is considerably lighter than ne (20.45 g / cm 3) and 钚 (19.8 g / cm 3), but it is heavier than most other metals. Between cur of the two crystal forms, α - Cm is more stable under ambient conditions. It has hexagonal symmetry, space group P 63 / mmc, lattice constants a = 365 pm and c = 1182 pm, and 4 recipe units per unit cell. The crystals consist of doubly hexagonal crystals packed closest packed with layered arrays ABAC and are therefore of the same type as α - α. These three current stages are also called Cm I, II and III.
Sulfide, selenide, and telluride cur are obtained by treating cur with gaseous sulfur, selenium or tellurium at elevated temperature in vacuo. CmX type cur phosphate is known as nitrogen, phosphorus, arsenic, antimony element. They can be prepared by reacting ruthenium hydride (III) (CmH 3) or metal carbonate with these elements at an elevated temperature. The Cm (n - C 3 H 7 - BTP) type 3 complex is formed in a solution containing n - C 3 H 7 - BTP, where BTP is 2,6 - bis (1,2,4 - triazine -3-yl) pyridine. EXAFS confirmed Cm 3+ ion. Some of these BTP type complexes are useful for selectively interacting with cur and thus selectively separating from lanthanides and other line of action elements. The dissolved Cm 3+ ion binds to many organic compounds such as hydroxamic acid, urea, fluorescein, adenosine triphosphate. Many of these compounds are related to the biological activity of various microorganisms.