Radioactive Disintegration Series
Category : JEE Main & Advanced
The phenomenon of natural radioactivity continues till stable nuclei are formed. All the nuclei from the initial element to the final stable element constitute a series known as disintegration series. Further we know that mass numbers change only when a-particles are emitted (and not when b-particles are emitted) causing the change in mass of 4 units at each step. Hence the mass numbers of all elements in a series will fit into one of the formulae. 4n, \[4n+1\], \[4n+2\] and \[4n+3\], hence there can be only four disintegration series.
| 4n | 4n + 1 | 4n + 2 | 4n + 3 | |
| \[n\] | 58 | 59 | 59 | 58 |
| Parent element | \[_{90}T{{h}^{232}}\] | \[_{94}P{{u}^{241}}\] | \[_{92}{{U}^{238}}\] | \[_{92}{{U}^{235}}\] |
| Half life (yrs) | \[1.39\times {{10}^{10}}\] | 10 | \[4.5\times {{10}^{9}}\] | \[7.07\times {{10}^{8}}\] |
| Half life (yrs) | \[1.39\times {{10}^{10}}\] | \[2.2\times {{10}^{6}}\] | \[4.5\times {{10}^{9}}\] | 13.5 |
| Name of series | Thorium (Natural) | Neptunium (Artificial) | Uranium (Natural) | Actinium (Natural) |
| End product | \[_{82}P{{b}^{208}}\] | \[_{83}B{{i}^{209}}\] | \[_{82}P{{b}^{206}}\] | \[_{82}P{{b}^{207}}\] |
| \[n\] | 52 | 52 | 51 | 51 |
| Number of lost particles | \[\alpha =6\] \[\beta =4\] | \[\alpha =8\] \[\beta =5\] | \[\alpha =8\] \[\beta =6\] | \[\alpha =7\] \[\beta =4\] |
You need to login to perform this action.
You will be redirected in
3 sec
