Question

What is the net charge on a neutral atom?
A. positive
B. negative
C. zero
D. None of these.

Answer 1

Hint: The terminology itself gives away the answer. The word 'neutral' always is used in a sense of balance, like when some negative quantity balances the positive. In an atom, electrons are negative and protons are positive.

Complete step by step answer:
An atom is the smallest fundamental unit of a substance. An atom is to a material, what a brick is to a wall. When we go inside this atom, there is a further distribution of charge particles. An atom is further subdivided into particles called electrons, protons and neutrons. Electrons and protons have equal charge valves but different masses. A proton is around 1000 times heavier than an electron. But, when we talk about the neutrality of atoms, we talk about the charge balancing only. It was John Dalton, who first gave a theory that the atom must be neutral as we don't observe charge so frequently. Consider static electricity examples of daily life, we observe an interaction between the charges there. This happens due to the transfer of electrons. When there is an excess of electrons, a substance becomes negatively charged, when there is a deficiency, it becomes positively charged.
An atom has a positively charged nucleus with negatively charged electrons surrounding it. Since the charge of the nucleus is the same as the total charge of the electrons, a neutral atom has a net zero charge.

So, the correct answer is “Option C”.

Additional Information: The atomic model, as appears so simplistic now, was not so about 100 years back. It was Niels Bohr who pioneered the research in this field after working with and learning from Rutherford. Bohr gave an intuitive model back then, which now is adapted as a general atomic model. His predictions matched the experiments.

Note: The neutrality of a system depends on the perspective. Consider a system with two unequal but opposite charges. If we observe a dipole from far distances it appears to act like a monopole. Therefore, if we set out the frame inside the atom, it might not have a net charge zero.