In alpha decay 2 protons and two neutrons are lost by an atom
Does the number of elcetrons reamin same

Asked by lovemaan5500 | 21st Dec, 2017, 04:36: PM

Expert Answer:

in alpha decay atomic number of alpha emiiting nucleus reduced by 2 and the alpha emitting nucleus is changed into different type of element.
 
For example in the following equation, Uranium is changed to thorium after alpha emission.
 
begin mathsize 12px style U presubscript 92 superscript 238 space rightwards arrow space T presubscript 90 h to the power of 234 plus space H presubscript 2 e to the power of 4 end style
In this radioactive decay, thorium is neutral/excited atom but can have 90 electrons only, but the alpha particle is helium nucleus it does not have electrons. since Uranium is metal, the excess two electrons reside in the uranium metal as free eletrons and stay at the surface as surface charge

Answered by  | 22nd Dec, 2017, 12:35: PM