[
UK
/pɹəʊmˈiːθiəm/
]
[ US /pɹəˈmiˌθiəm/ ]
[ US /pɹəˈmiˌθiəm/ ]
NOUN
- a soft silvery metallic element of the rare earth group having no stable isotope; was discovered in radioactive form as a fission product of uranium
How To Use promethium In A Sentence
- Mythological characters that can be found on the periodic table include Tantalus (Tantalum, Ta) and his daughter Niobe (Niobium, Nb), and Promethius (Promethium, Pm).
- In fact, the elements with atomic numbers 43, 61, and 85 (technetium, promethium, and astatine, respectively) were unknown on earth until some of their radioactive isotopes had been produced synthetically.
- The only missing one was element number 61, which was eventually isolated from the debris of the radioactive decay of uranium and given the name of promethium, after the Greek god who gave man fire.
- They aimed beams of heavy ions at targets of selected elements to produce nuclei with 75 neutrons and 55, 57, 59, and 61 protons (cesium, lanthanum, praseodymium, and promethium) in a wide variety of spin states.
- Finally in 1945, scientists isolated promethium from uranium fission products purified by ion-exchange chromatography.
- Of course this is no promethium, but it could look like that: an otherwise typical lanthanoid, which however due to its radioactivity produces quite some heat and therefore on the surface quickly oxidizes to pink Pm2O3. CreationWiki - Recent changes [en]