All matters in this universe are made up of very small atoms. The atoms consist of particles that are positively, negatively, and neutrally charged. Positive charge is called proton, negative charge is called electron, and neutral charge is called neutron.
An atomic nucleus consists of protons and neutrons surrounded by electrons that move continuously. Electrons in the atom can escape or enter into the composition of an atom. If the electrons escape from the composition of an atom, the number protons in the atom is more than the number of electrons, so the atom becomes positively charged. Meanwhile, if the electrons enter to the composition of an atom, the number of protons in the atom is less than the number of electrons, so the atom becomes negatively charged. The atom will have neutral property (uncharged) if the number of protons in the atomic nucleus is equal to the number of electrons that revolve around the atomic nucleus.
It can be concluded that a neutral body can be statically charged by rubbing it. Another example is when a plastic rod is rubbed with a wool, the electrons from the wool move to the plastic rod, so the plastic rod ha excessive electrons. Hence, the plastic rod becomes negatively charged. On the contrary, when a glass rod is rubbed with silk electrons from the glass rod move to the silk, so the glass rod lacks electrons. Accordingly, the glass rod becomes positively charged.
