Alpha Particle Emission & Neutron Imbalance

[Abhishek ad]

Alpha particle emits when no. of neutrons in an atom are much more...
My ques. Is that the no. Of protons and neutrons emitted are same so the substance formed after the reaction should still have much more neutrons than protons..
Infact mathematically the ratio increases.

 

[e.bar.goum]

Alpha particle emits when no. of neutrons in an atom are much more...

This is not true. Look at this nuclide chart. http://upload.wikimedia.org/wikipedia/commons/7/79/NuclideMap_stitched_small_preview.png

Alpha emitting nuclei are shown in yellow. You can see that these nuclei tend to the proton rich side of stability, until you reach the superheavies, and they're all unstable to alpha emission.