放射性物质由很多不稳定原子构成。
Radioactive materials are composed of atoms that are unstable.
每个元素至少有一个同位素不稳定原子核可以进行放射性衰变。
Each element has at least one isotope with unstable nuclei that can undergo radioactive decay.
不稳定原子在达到稳定状态前，需要释放出自身多余的能量，这一能量即辐射。
An unstable atom gives off its excess energy until it becomes stable. The energy emitted is radiation.
“这些生物从一个我们从未想到的来源获取能量，”McKay惊叹，“南非的极端微生物细菌吃的是岩石里不稳定原子衰变时的放射能。”
"These creatures get their energy from sources we never imagined," McKay exclaims. "the South African extremophile bacteria are powered by the radioactive decay of unstable atoms in the rocks."
在这个原子钟的装置里，它们还是太不稳定了，不能靠自身确保时间。
At the esoteric edge of the timekeeper's craft, they are too wobbly to keep time by themselves.
不稳定的原子释放出多余的能量，直到变得稳定。
An unstable atom gives off its excess energy until it becomes stable.
原子通过辐射由不稳定状态转变为更加稳定状态的过程称为放射性衰变或放射性。
The process by which an atom changes from an unstable state to a more stable state by emitting radiation is called radioactive decay or radioactivity.
当原子不稳定时，会具有放射性。
有些可能的试剂非常不稳定，需在低温下使用，但是，如果一个原子的几乎是惰性的气体消除了，就能够让化学过程简化多了。
Some of the potential reagents are very fragile and will need to be used at cryogenic temperatures, but the elimination of an atom of an almost inert gas can simplify the chemistry.
这种原子通过释放射线从不稳定状态变到更加稳定的状态的过程被称为核衰减或放射。
The process by which an atom changes from an unstable state to a morestable state by emittingradiation is called radioactive decay or radioactivity.
那么，如果我们放出了能量，你认为氯离子比氯原子，更稳定还是更不稳定呢？
So, if we have energy that's released, would you say that the chlorine ion is more or less stable than the chlorine atom?
在此之前，2维碳原子片一直被认为是不稳定的。
Previously, two-dimensional carbon sheets weren't thought to be stable.
但他们指出，虫洞可能是不稳定的，或者强烈辐射和亚原子力周围的虫洞的入口会杀死任何人谁也不敢进去。
But they point out that wormholes might be unstable, or that intense radiation and sub-atomic forces surrounding the entrance to the wormhole would kill anyone who dared to enter.
原子激发态是不稳定的，其必然会自发地向低能级衰变，产生自发辐射现象。
Atom's motivated state in not stable, it inevitably disintegrate into the lower energy state, which makes the phenomenon of the spontaneous radiation.
例如有机锡的稳定剂可以和羧甲基纤维素分子的不稳定氯原子配位结合，有机锡和不稳定的氯原子发生置换反应。
For example, the stabilizer of organotin compounds can be combined with the unstable chlorine atom of the carboxymethyl cellulose molecule, and the organotin and unstable chlorine atoms are replaced.
当一个中子轰击一个原子核的时候，这个核可能会俘获这个中子，从而变的极不稳定。
When a neutron hits an atomic nucleus, the nucleus can absorb the neutron and become unstable.
在自然界，凡原子核不稳定，过一些时间自发地变成其它元素原子核的元素，称为放射性元素。
In nature, the element, whose nucleus is unstable and will grows to be nuclear of other element, is called radioactive element.
在自然界，凡原子核不稳定，过一些时间自发地变成其它元素原子核的元素，称为放射性元素。
In nature, the element, whose nucleus is unstable and will grows to be nuclear of other element, is called radioactive element.
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