The properties of electric charge are:
(1) QUANTIZATION OF ELECTRIC CHARGE: It is the property by virtue of which all free charges are integral multiple of the charge of an electron or a proton. The cause of quantization is that only integral number of electrons can be transferred from one body to another.
(2) Conservation of Electric Charge: The total charge of an isolated system is always conserved.
Coulomb’s Law states that the force between two point charges is directly proportional to the product of the chargers, and, inversely proportional to the square of the distance between them.
You may have learned Coulomb’s Law in lower classes and solved some numerical problems too. But in class 12 and entrance exams like NEET and IIT-JEE, the numerical problems based on Coulomb’s law are much more difficult.