Quantization of charge states that charge (q) on a body exists as an integral multiple of charge on one electron (e).
Mathematically it can be expressed as
q = n e
Where,
e = charge on one electron = 1.6 × 10−19
n = 0 , 1 , 2 ............... (postive or negative integers )
Suppose charge on a body is 1 × 10−19,
For this case,
n=qe=1 × 10−191.6 × 10−19= 0.625
As, n = 0.625 is not an integer, so this amount of charge is not possible to exist on a body.