A body 'P' contains 50 electrons and 45 protons and a body 'Q' contains 72 electrons and 77 protons after electrification by friction between the bodies. Find the number of electrons and protons in 'P' and 'Q' before electrification. Also find the number of electrons transferred between them.

Explanation

(i) During electrification, transfer of only valence electrons but not protons.
(ii) Number of electrons= Number of protons in a neutral body.
(iii) P- 45 e, 45 P
Q - 77 e, 77 P
P gained 5 electrons.