Question

If the number of protons and electrons are same, the charge is neutral and we don't feel it .But when a metal is there and we hit it with the other the electrons are free. Then at that very moment,why don't we feel any charge?

Answer 1

To understand the answer, you need to know the concept of kernels. 'kernels' are pools of electrons inside a metal. Electrons can freely move within this kernel but for any reaction i.e. discharge of electron to happen, it requires some energy.

Now, when you hit two metal together that energy is too less to break the chemical bonds within a kernel for it to get discharged from the metal. All that happens is the instantaneous velocity of electrons with the kernels is increased for sometime but the electron does not even come on the outer surface of the metal, let alone escape. Thus, you do not feel any charge.

Rubbing two metals against each other does generate a charge but that happens not because of electrons but because of conduction. The same reason why small bits of papers are attracted to a ruler charged by rubbing on hair.