放射性元素

All are radioactive heavy metals; and only the first four (actinium, thorium, protactinium, and uranium) occur in nature in appreciable quantities. The other 11 are unstable and are produced only artificially.

这些元素都是具有放射性的重金属；仅前四个元素是在自然界中存在的，其余十一个都不稳定且均为人造的。

The Curies tried to compare their rays with Becquerel's rays, to find the commonalties.

居里夫妇试着对这两种元素的射线与贝克雷尔的射线进行了比较，以便找到具有放射性的元素郡体。

Radioactive decay studies have found a kinds of elements can be α or β decay and the decay into another element, while the α-decay product of -α-rays became one of the deep structure of the material means of .1911, the Rutherford and others bombarded atoms with α-rays observed wide-angle deflection to determine the nuclear structure of atoms and nuclei was first proposed the term .1919 year, Rutherford and others have also found that with α-ray bombardment of nitrogen will release the nuclear protons, this is the first time Artificial realization of a nuclear reaction, after the bombardment of nuclei with the radiation caused by nuclear reaction method to become the primary means of research in nuclear.

放射性衰变研究发现了一种元素可以通过α衰变或β衰变而变成另外一种元素，而α衰变的产物——α射线又成了人们探讨物质深层结构的手段。1911年，卢瑟福等人用α射线轰击原子、观察到大角度偏折，从而确定了原子的有核结构，并首次提出原子核这一名词。1919年，卢瑟福等人又发现用α射线轰击氮核会放出质子，这是首次用人工实现的核反应，以后用射线轰击原子核来引起核反应的方法逐渐成为研究原子核的主要手段。

Radioisotope means the nuclide in a certain element with radioactive decay, which has the same ordinal number of atoms but different mass.

放射性同位素，是指某种发生放射性衰变的元素中具有相同原子序数但质量不同的核素。

Group in the periodic table there are silver-white metallic luster of the solid metal transition element, atomic number Z = 26, atomic weight of 55847, chemical symbol Fe, there is a stable F isotope 5626Fe and a radioisotope 5526Fe, content of 5% of the earth's crust, accounting for elements of in the fourth place, the metal in the second melting point 1535 ℃, boiling point 2750 ℃, the relative density of 786, the external electronic structure 3d64s2, chemical reactions 2-6 tram F-volatile son, oxidation number of 0, 2, 3, 4 , 5 and 6, the chemical nature of the metal element is very lively, in the humid air combined with oxidation, but also directly with the sulfur, phosphorus, silicon, carbon together.

周期表中Ⅷ族有银白色金属光泽的固体金属过渡元素，原子序数Z＝26，原子量55847，化学符号Fe，有一种稳定F同位素5626Fe和一种放射性同位素5526Fe，地壳中含量5％，占元素中第四位、金属中第二位熔点1535℃，沸点2750℃，相对密度786，外围电子结构3d64s2，化学反应时易丢失2—6个电F子，氧化数为0、＋2、＋3、＋4、＋5和＋6、化学性质很活泼的金属元素，在潮湿空气中能与氧化合，也能直接与硫、磷、硅、碳化合。

In reality the proportion of the hypothetical element was far lower and it took several years to show unequivocally that ''.'pitchblende'.

实际上这种假设中的元素的浓度要小得多，我们花了几年时间才明确无误地证明沥青铀矿物质中至少含有一种高放射性物质，在化学意义上这就是一种新元素。

For instance, a compound can be synthesized with one of the atoms replaced by a radioactive isotope of the element.

例如，用某种放射性元素来代替原来的元素合成某一化合物，则放射性就可追踪这一化合物的合成过程。

Marie had linked the relationship between radioactivity to individual atoms in her first solo paper. The source of the radioactive energy. however, was still a mystery.

玛丽在她首先独自发表了论文中，关联了在放射性与单个原子之间的关系，然而元素放射性的来源仍然是一个谜。

Activity exceeds 75 becquerels of parent radioactive chemical element per gram of substance.

成的任何物质，或包含该等元素的任何物质，而其放射性比，以每克物质计算，超逾75贝克耳的源放射性化学元素。

Activity exceeds 75 becquerels of parent radioactive chemical element per gram of substance.

或包含该等元素的任何物质，而其放射性比，以每克物质计算，超逾75贝克耳的源放射性化学元素。

Neither the killing of Mr Zarqawi nor any breakthrough on the political front will stop the insurgency and the fratricidal murders in their tracks.

在对危险的南部地区访问时，他斥责什叶派民兵领导人对中央集权的挑衅行为。

In fact,I've got him on the satellite mobile right now.

实际上 我们已接通卫星可视电话了