posted by Marty on .
If a polonium-210 (Po-210) atom has just decayed, how close can the ejected
alpha particle get to a neighboring Po-210 nucleus?
Hint: W = F*r
The particle has initial KE, lets say K.
That energy can be converted to PE as it approaches the nucleus.
When equal, the particle can go no further.
K= INTEGRAL F*dr= -kq1q2/r evaluated from infinity to x
so the minimum distance x= kq1q2/K
So look up the energy lost when the Po nucleus decays, the charge on the decayed nucleus, and the charge on the alpha particle. Then, it is just calculator work.
I don't quite understand
According to my physics text, Po-210 decays by alpha decay, leaving an alpha particle (+2e charge) , a Pb-206(-2) ion that will eventually neautalize, and 45.17 - 36.15 = 9.02 MeV of energy.
Most, but not all, of the energy will be kinetic energy of the alpha particle. The adjacent Po atom has nuclear charge of +84 e.
They probably expect you to ignore the energy loss as the alpha particle penetrates the electron cloud around the Po atom.
Where does the 45.17-36.15 come from and the +84 e?