Nature, most elements have two or more isotopes, the same kinds of elements in the quality of the various isotopes of different, but the types and proportion constant (except for radioactive elements). In 1961, the carbon content of the most abundant in nature, a kind of isotope, carbon-12 atom of a quantity and quality of C as a 12 mass units to it as "benchmarks" for all isotopes of an element according to the average abundance The ratio of the benchmark is the atomic weight of this non-prime, that is listed in the periodic table of atomic weights.

自然界中大多數(shù)元素都有兩種或更多的同位素超碰人人色人人操，同種元素的各同位素質(zhì)量不同国产91精品专区，但其種類和比例是恒定的91色色福利。1961年，把碳在自然界含量最豐富的一種同位素嫩草久久久久久久精品99，碳12的一個(gè)原子的質(zhì)C量定為12個(gè)質(zhì)量單位，把它作為"基準(zhǔn)"亚洲视频黄色，某種元素的所有同位素按豐度的平均值與基準(zhǔn)之比黄色视频直接进，就是這種無(wú)素的原子量，即元素周期表列出的原子量免费三级视频网站。

A short-lived radioactive metallic element formed from uranium and disintegrating into actinium and then into lead.

一種存在周期短的放射性金屬元素亚洲人成A片在线观看尤物，由鈾形成，能分裂成錒然后分裂成鉛欧美综合色婷婷欧美综合五月。

A radioactive transuranic element; discovered by bombarding americium with helium.

一種放射性超鈾元素免费无码黄视瓶，在用氦轟擊镅時(shí)發(fā)現(xiàn)。注意国产一级激情免费视频，注意力集中

Any element having an atomic number greater than 92; all are radioactive.

原子序數(shù)在以后的元素亚洲R在线，都是放射性元素。

A radioactive transuranic element synthesized by bombarding curium with carbon ions; 7 isotopes are known.

一種放射性超鈾元素一级无遮挡真人毛片A片，用碳離子轟擊鋦而合成97超碰免费，已知有種同位素。

A radioactive transuranic element; discovered by bombarding curium with alpha particles.

一種放射性超鈾元素国产在线对白视频黄，在用α粒子轟擊鋦時(shí)發(fā)現(xiàn)18禁美女裸体啪啪免费网站。

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.

放射性衰變研究發(fā)現(xiàn)了一種元素可以通過(guò)α衰變或β衰變而變成另外一種元素理论日韩中文，而α衰變的產(chǎn)物——α射線又成了人們探討物質(zhì)深層結(jié)構(gòu)的手段超碰在线欧美精品。1911年，盧瑟福等人用α射線轟擊原子欧美又大又粗一区二区、觀察到大角度偏折偷拍视频无码，從而確定了原子的有核結(jié)構(gòu)，并首次提出原子核這一名詞亚洲色欲综合网在线观看A。1919年欧美一级视频网站免费在线观看，盧瑟福等人又發(fā)現(xiàn)用α射線轟擊氮核會(huì)放出質(zhì)子，這是首次用人工實(shí)現(xiàn)的核反應(yīng)成年无码av网站天堂网，以后用射線轟擊原子核來(lái)引起核反應(yīng)的方法逐漸成為研究原子核的主要手段久久精彩视频7。

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，是指某種發(fā)生放射性衰變的元素中具有相同原子序數(shù)但質(zhì)量不同的核素黄片aaav免费。

The immediate product of the radioactive decay of an element.

一種堿金屬屬的放射性元素亚洲欧洲黄色搞j国产网站VV级，是錒瓦解的產(chǎn)物。

Each element has at least one isotope with unstable nuclei that can undergo radioactive decay .

每個(gè)元素至少有一個(gè)同位素不穩(wěn)定原子核可以進(jìn)行放射性衰變色欲天天婬色婬香综。