Q :If number of electrons in an atom is 8 and number of protons is also 8, then (i) what is the atomic number of the atom and (ii) what is the charge on the atom?

ANS:(i) The atomic number is equal to the number of protons. Therefore, the atomic number of the atom is 8.

(ii) Since the number of both electrons and protons is equal, therefore, the charge on the atom is 0.

 

My Q: Why is the charge on the atom 0????

A neutral atom has equal number of protons and electrons. Because its positive and negative charges are equal, it has no overall electrical charge, or has an overall charge of zero. The charge balance is what gives the neutral atom its overall charge of zero. 

.. these r neutral atoms..because they r neutral in charge...v know that neutral atoms do not have an overall charge since the number of protons equals the number of electrons. But an atom can have a charge if it is what is called an ion. When an atom borrows or loans out electrons, it forms an ion, and this ion has a charge. The charge on any atom that is an ion is based on the number of electrons it has borrowed or loaned out.

Atoms with negative charges have borrowed electrons, and atoms with positive charges have loaned out electrons. For each electron borrowed or loaned, we count "1" and then add them up. An atom that has loaned out 3 electrons has an overall charge of +3, and an atom that has borrowed 2 electrons has an overall charge of -2. It really is just that simple.