Question

There is a reduction of 500electron then find the quantity of charge and it's nature

Answer 1

Charge only comes in countable numbers. The smallest amount of charge that has ever been observed is the charge on the electron and/or the charge on the proton (both the same amount, but opposite type). Hence the term "quantization of charge." Quantum or "quantized" means that it is numbered or integer-countable (can come in -1, 0, 1, 2, 3, etc. but not 1.5 or pi, etc), and a quantum is essentially one of those quantized objects. The total charge on a charged object is therefore the number of individual charges, all of which are either electrons or protons, multiplied by the charge on one of them. This explains the existence of the following equation:

Q=n*e