Grigoriy S. answered • 07/18/22
AP Physics / Math Expert Teacher With 40 Years of Proven Success
Michael, you asked an excellent question that, unfortunately, nobody could answer. It is the fundamental concept. But we can describe the properties of the bodies that are charged.
We found out experimentally that there are only two kinds of charges, and we gave them names positive and negative. The name is not important. Say, we can call them red and white. What is important that there are only TWO different charges. We accepted the suggestion by Franklin to call the charge positive, if it is appeared on a glass rod rubbed with the silk cloth. It is understandable that this choice is arbitrary.
The carriers of the charges are elementary particles. Proton has the smallest positive charge and the electron has the smallest negative charge. What is amazing that the magnitudes of the smallest negative and positive charges are the same. But masses of the particles are not comparable. Mass of the proton is 1837 times greater than that of electron. We do not understand why the proton has volume but electron we consider as point particle. The charge is an intrinsic property of proton or electron. We can take off the coat from a person but we cannot "take off" the charge from the charged elementary particles. Sure there are particles that do not have charges. Neutron is an example.
Like charges repel each other, unlike - attract. The total charge of any charged body is equal (as Milliken found out) to the whole number of elementary charges.
The most important property of the charge - is that it is conserved. It means that when we charge the body in reality we do not create new charges, we just separate them. To say that the body gained the positive charge ( glass rod) means that the body lost some electrons, and another body (silk cloth) acquired exactly the same amount of them.
Hope that my explanation will be helpful for you.
