POSITIVE AND NEGATIVE CHARGE CARRIES

Every matter is composed of a large number of small particles (Atomic hypothesis). It is easy to

 Think that if two charged bodies attract or repel one another, it is due to attraction or repulsion between the constituent particles. This leads us to think that the constituent particles must also be of two types- positively charged particles and negatively charged particles. Since matter is normally electrically neutral, the number of negatively charged particles and that of positively charged particles must be equal in them. But if we add some positively charged particles in a neutral matter, it would become positively charged. Similarly if we take our some negatively charged particles from a neutral matter it also would show excess positive charge. The same thing happens for negatively charged bodies

We have seen that a glass rod rubbed with silk becomes positively charged. There are two possibilities while rubbing, some positively charged particles from silk move to the glass rod, or some of the negatively charged particles in the glass transfer to the silk. What exactly happens? The answer comes from the structure of atoms.

It is known form school science that very light particles- electrons- continuously revolve around the nucleus in an atom. Electrons are negatively charged particles. The mass of nucleus is very large in comparison to the mass of an electron. The charges on the protons, which makes the nucleus, and on an electron are numerically equal, but they are of opposite types.

Nucleus is made of neutrons and protons (except for hydrogen in which the nucleus consists of just one proton). Neutrons are electrically neutral. In an atom, the number of protons inside the nucleus is equal to the total number of electrons revolving around it. An atom has equal amount of positive and negative charge and hence, it is electrically neutral.

When two object are rubbed, only one electrons move from atoms in one substance and transfer to the other objects, because they are light ( and therefore, easy to remove). When electrons are removed the objects becomes positive charged. This indicates deficiently of the electrons in it. On the other hand if we put some electrons on a substance, it becomes negatively charged. Clearly, it is an indication of excess electrons on it. Therefore, ordinary electrons and not protons are responsible for electrification of any object.