| 释义 |
promethium Chem.|prəʊˈmiːθɪəm|
orig. -eum.
[mod.L.: see Prometheus and -ium.]
An artificially produced metallic element (traces of which have subsequently been found in nature) which is a lanthanide whose longest-lived isotope has a half-life of about 18 years. Atomic number 61; symbol Pm. Cf. illinium.
1948Marinsky & Glendenin in Chem. & Engin. News 9 Aug. 2348/2 We propose, therefore, the name ‘prometheum’ (symbol Pm) for element 61 after Prometheus,..who stole fire from heaven for the use of mankind... This name..symbolizes the dramatic way in which the element may be produced in quantity as a result of man's harnessing of the energy of nuclear fission. 1949Sun (Baltimore) 22 Sept. 21/4 An element 500 times ‘hotter’ than radium is being studied... It is promethium, one of the rare earth metals. 1955T. D. O'Brien et al. in Sneed & Brasted Comprehensive Inorg. Chem. IV. vi. 184 Promethium comes between neodymium and samarium in the lanthanide series. It has an oxidation number of + 3 and possibly + 4. 1959Seaborg & Valens Elements of Universe 126 Promethium was discovered as a result of its artificial production in the atomic reactor. Ibid., Promethium nitrate is a rather undistinguished-looking powder. 1976Cotton & Wilkinson Basic Inorg. Chem. xxvi. 450 Promethium occurs only in traces in U ores as a spontaneous fission fragment of 238U. Milligram quantities of pink 147Pm3+ salt can be isolated..from fission products in spent fuel of nuclear reactors. |