promethium
/prəʊˈmiːθɪəm/noun
mass noun
- the chemical element of atomic number 61, a radioactive metal of the lanthanide series. It was first produced artificially in a nuclear reactor and occurs in nature in traces as a product of uranium fission. (Symbol: Pm)（化学元素）钷（符号： Pm）。
词源
1940s: modern Latin，from the name of the Titan PROMETHEUS.