promethium   (TTS Sound)

The promethium has 1 Senses.

• atomic number 61, promethium, pm
• プロメチウム, Pm, Ｐｍ
• 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
• 安定した同位元素を持たないまれな土群の柔らかい銀質の鉄分要素