| 单词 | 放射性元素 |
| 释义 | 〔meitnerium〕An artificially produced radioactive element with atomic number 109 whose most long-lived isotopes have mass numbers of 266 and 268 with half-lives of 3.4 milliseconds and 70 milliseconds, respectively. Also called unnilennium ：人工产生的放射性元素，原子序数号为109，生命期最长同位素的质量为266和268，半衰期分别为3.4毫秒和70毫秒 也作 unnilennium〔bohrium〕An artificially produced radioactive element with atomic number 107 whose most long-lived isotopes have mass numbers of 261, 262, and 264 with half-lives of 11.8 milliseconds, 0.1 seconds, and 0.44 seconds, respectively. Also called unnilseptium ：人工产生的放射性元素，原子序数号为107，生命期最长同位素的质量为261、262和264，半衰期分别为11.8毫秒、0.1秒和0.44秒 也作 unnilseptium〔Aston〕British chemist and physicist. He won a 1922 Nobel Prize for developments that led to the discovery of isotopes in nonradioactive elements.阿斯顿，弗朗西斯·威廉：(1877-1945) 英国化学家及物理学家。他因在非放射性元素的同位素的发现过程中取得重大进展而获1922年诺贝尔奖〔astatine〕A highly unstable radioactive element, the heaviest of the halogen series, that resembles iodine in solution. Its longest lived isotope has a mass number of 210 and has a half-life of 8.3 hours. Atomic number 85; melting point 302°C; boiling point 337°C; valence probably 1, 3, 5, 7. See table at element 砹：极不稳定放射性元素，在卤族元素比重最大，在溶解状态与碘相象，它最长周期的同位素原子量为210，半衰期为8.3小时。原子序数85；溶点302°C；沸点337°C；化合价可能为1、3、5、7 参见 element〔mutagen〕An agent, such as ultraviolet light or a radioactive element, that can induce or increase the frequency of mutation in an organism.诱变剂：有机体中的一种可诱发或者增加突变的次数的因子，如紫外线或放射性元素〔hassium〕An artificially produced radioactive element with atomic number 108 whose most long-lived isotopes have mass numbers of 264 and 265 with half-lives of 0.08 milliseconds and 2 milliseconds, respectively. Also called unniloctium ：人造放射性元素，原子序数号为108，生命期最长同位素的质量为264和265，半衰期分别为0.08毫秒和2毫秒 也作 unniloctium〔dubnium〕An artificially produced radioactive element with atomic number 105 whose most long-lived isotopes have mass numbers of 258, 261, 262, and 263 with half-lives of 4.2, 1.8. 34, and 30 seconds, respectively. Also called unnilpentium ：人造放射性元素，原子序数号为105，生命期最长同位素的质量为258、261、262和263，半衰期分别为4.2秒、1.8秒、34秒和30秒 也作 unnilpentium〔seaborgium〕An artificially produced radioactive element with atomic number 106 whose most long-lived isotopes have mass numbers 259, 261, 263, 265, and 266 with half-lives of 0.9, 0.23, 0.8, 16, and 20 seconds, respectively. Also called unnilhexium ：人工产生的放射性元素，原子序数号为106，生命期最长同位素的质量为259、261、263、265和266，半衰期分别为0.9秒、0.23秒、0.8秒、16秒和20秒 也作 unnilhexium〔actinium〕A radioactive element found in uranium ores, used in equilibrium with its decay products as a source of alpha rays. Its longest lived isotope is Ac 227 with a half-life of 21.7 years. Atomic number 89; melting point 1,050°C; boiling point (estimated) 3,200°C; specific gravity (calculated) 10.07; valence 3. See table at element 锕：一种在铀矿中发现的放射性元素，作为阿尔法射线能源增入点用于与其衰变产物的平衡过程中，其最长的活同位素是半衰期为21.7年的锕227。原子序数为89；熔点为1,050摄氏度；（估计的）沸点为3,200摄氏度；（计算出的）比重为10.07；原子价为3 参见 element〔californium〕A synthetic element produced in trace quantities by helium isotope bombardment of curium. All isotopes are radioactive, chiefly by emission of alpha particles. Atomic number 98; mass numbers 244 to 254; half-lives varying from 25 minutes to 800 years. See table at element 锎：一种合成元素，由氦同位素轰击锔可得到微量的这种元素。所有同位素均是放射性元素，主要放射出α粒子。原子序数98；原子量244到254；半衰期从25分钟到800年不等 参见 element〔radioelement〕A naturally occurring or artificially produced radioactive element.放射性元素：自然产生或人为制造的放射性元素〔actinide〕Any of a series of chemically similar, radioactive elements with atomic numbers ranging from 89 (actinium) through 103 (lawrencium).锕类：任何化学性质相似，原子序数在89（锕）与103（铹）之间变化的放射性元素〔neptunium〕A silvery, metallic, naturally radioactive element, atomic number 93, the first of the transuranium elements. Its longest-lived isotope is Np-237 with a half-life of 2.1 million years. Found in trace quantities in uranium ores, it is produced synthetically by nuclear reactions. See table at element 镎：一种银白色的、金属性天然放射性元素，原子序数为93，第一个超铀元素。其周期最长的同位素为Np-237，半衰期为210万年。见于铀矿的示踪量中，由核反应合成生产出来 参见 element〔protactinium〕A rare, extremely toxic, radioactive element chemically similar to uranium, having 13 known isotopes, the most common of which is protactinium 231 with a half-life of 32,480 years. Atomic number 91; melting point 1,230°C; specific gravity 15.37; valence 4, 5. See table at element 镤：一种稀有的、剧毒放射性元素，在化学性质上与铀相似。有十三个已知的同位素，其中最常见的是半衰期为32,480年的镤231。原子序数为91；熔点1,230°C；比重15.37；原子价4, 5 参见 element |
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