Question

The existence of a negative charge on a body implies that it has:
(A) Lost some of its electrons
(B) Lost some of its protons
(C) Acquired some electrons from outside
(D) Acquired some protons from outside

Answer 1

Hint: We should know that the electrons exist as point charges with a size of zero. To say that an object has mass and no size is to say that it has infinite density. It is thus more realistic to suggest that an electron does have a non-zero size, even though it is exceedingly small and irrelevant in most considerations. Electrons have the smallest electrical charge. This electrical charge equals the charge of a proton, but has the opposite sign. For this reason, electrons are attracted by the protons of atomic nuclei and usually form atoms. An electron has a mass of about 1/1836 times a proton.

Complete step by step answer
We know that electrons are subatomic particles that hold an elementary charge of magnitude -1. The charge of an electron is equal in magnitude to the charge held by a proton (but has an opposite sign). Therefore, electrically neutral atoms/molecules must have an equal number of electrons and protons. Electrons are fundamental particles so they cannot be decomposed into constituents. They are therefore not made or composed. An electron acts as a point charge and a point mass.
Another conserved quantity is electric charge. And since the electron is the lightest particle that has electric charge, there is nothing that it can decay to; only neutrinos, photons, gluons and gravitons are lighter, but they are all electrically neutral, so any combination of them would have zero electric charge.
It is known that negative charge acquired on a body implies that it has a greater number of electrons than the number of protons.
 Hence a body is negatively charged by acquiring some electrons from outside.

So, the correct answer is option C.

Note: We know that electrons are also important for the bonding of individual atoms together. Without this bonding force between atoms matter would not be able to interact in the many reactions and forms we see every day. This interaction between the outer electron layers of an atom is called atomic bonding. It can occur in two forms. Electrons are not actually massless, of course; the effective mass is a parameter that describes how an electron at particular wave vectors responds to applied forces. The electrical pressure due to the difference in voltage between the positive and negative terminals of a battery causes the charge (electrons) to move from the positive terminal to the negative terminal.