| 释义 |
plu·to·ni·um AHD[plo͞o-tōʹnē-əm] D.J.[pluːˈtəʊniːəm]K.K.[pluˈtoniəm]n.Symbol Pu （名词）符号 Pu - A naturally radioactive, silvery, metallic transuranic element, occurring in uranium ores and produced artificially by neutron bombardment of uranium. Its longest-lived isotope is Pu 244 with a half-life of 76 million years. It is a radiological poison, specifically absorbed by bone marrow, and is used, especially the highly fissionable isotope Pu 239, as a reactor fuel and in nuclear weapons. Atomic number 94; melting point 640°C; boiling point 3,235°C; specific gravity 19.84; valence 3, 4, 5, 6. See table at element 钚：一种天然地放射性银色超铀金属元素，存在于铀矿中，对铀元素进行中子轰击而人工制成。其存在周期最长的同位素是半衰期为七千六百万年的钸244，它是一种核辐射毒素，特别是能被骨髓吸收。尤其是其极具可裂变性的同位素钸239，被用作一种核反应燃料并用在核武器中。原子序数94；熔点640°C；沸点3,235°C；比重19.84；化合价3, 4, 5, 6 参见 element
- After the planet Pluto [from the fact that it follows neptunium in the periodic table] 源自 Pluto [源于该元素在元素周期表中排在铼之后这一事实]
|