Radioactive series

Radioactive series refers to the radioactive decay of different unstable elements (called radioactive elements) until a stable nuclei is formed. There are four radioactive series, three of which are natural (Uranium series, Thorium series and Actinium series) and the fourth (Neptunium series) is an artificial radioactive series.

Uranium series:

 In this series the parent element is uranium ₉₂U²³⁸ and the end product of this series after theemission of six α particles and five β particles is obtained as radium lead (₈₂Pb²⁰⁶) which is indistinguishable chemically from the ordinary lead and it is a stable isotope of lead.

 

Thorium series:

  The parent element of this series is Thorium- ₉₀Th²³². It goes through a series of transformations in many respects similar to the uranium series and ends with a stable isotope

(₈₂Pb²⁰⁸).

 

Actinium series:

 The parent element of this series is an isotope of Uranium called action Uranium- ₉₂U²³⁵  and its end product is again a stable isotope of lead (₈₂Pb²⁰⁷).

 

Neptunium series:

 After the discovery of the unstable transurenic elements (the elements of atomic number greater than 92 are called transurenic elements), another radioactive series was traced out. This is called neptunium series and is named after its longest living member Neptunium. It doesn’t end in a stable isotope of lead  but in a stable isotope of Bismuth (₈₃Bi²⁰⁹).