An alpha nucleus of energy $${1 \over 2}m{v^2}$$ bombards a heavy nuclear target of charge $$Ze$$. Then the distance of closest approach for the alpha nucleus will be proportional to

When $${}_3L{i^7}$$ nuclei are bombarded by protons, and the resultant nuclei are $${}_4B{e^8}$$, the emitted particles will be

If radius of the $$\matrix{ {27} \cr {13} \cr } $$ $$Al$$ nucleus is estimated to be $$3.6$$ fermi then the radius of $$\matrix{ {125} \cr {52} \cr } \,Te$$ nucleus is estimated to be nearly

Starting with a sample of pure $${}^{66}Cu,{7 \over 8}$$ of it decays into $$Zn$$ in $$15$$ minutes. The corresponding half life is