Two identical spheres A and B having charges +8e and -5e are brought in contact for a moment. After that, I understand that the charge in each sphere will become (8-5)/2 = 1.5 e. Then how will the concept of quantization of charge (Q=ne) will hold ?

Quantization of charge is about the transfer of integral number of electron from one conducting body to another wheather the process is of friction, conduction or induction./...
So Quantization of charge and charge conservation property is validated over here...

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