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.
- synonyms: Pm, atomic number 61
WordNet 3.0 © 2006 by Princeton University
| APA | WordNet. (2010). promethium. Retrieved September 20, 2026, from http://smartdefine.org/promethium/definitions/1247680 |
| Chicago | WordNet. 2010. "promethium" http://smartdefine.org/promethium/definitions/1247680 (accessed September 20, 2026). |
| Harvard | WordNet 2010, promethium, Smart Define, viewed 20 September, 2026, <http://smartdefine.org/promethium/definitions/1247680>. |
| MLA | WordNet. "promethium" 23 October 2010. Web. 20 September 2026. <http://smartdefine.org/promethium/definitions/1247680> |