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In the simplest terms, elements with unstable nucleus are known as radioactive elements. All the elements with an atomic number of more than 83 are radioactive elements. It also means that they do not possess any stable isotope. Some examples of radioactive elements are uranium, polonium, radon, radium, etc. There...

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In the simplest terms, elements with unstable nucleus are known as radioactive elements. All the elements with an atomic number of more than 83 are radioactive elements. It also means that they do not possess any stable isotope. Some examples of radioactive elements are uranium, polonium, radon, radium, etc. There could also be some elements that may have some stable and some unstable isotopes. All the unstable isotopes will also undergo radioactive decay and are known as radioactive isotopes. For example, Carbon-14 is a radioactive isotope of the element carbon.

An unstable nucleus will undergo decay and become stable. In the process of decay, it may emit any of the alpha, beta or gamma radiations. Half life is a useful concept associated with radioactive elements and isotopes. It is the time needed for a radioactive material to decay to 50% of its original value.

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