The protons and neutrons are in an atom by strong force. It is approximately 137 times stronger than electromagnetic force and 10⁵ times stronger than weak force. Also, it is billion times stronger than gravitational force.
An atom consists of electrons, protons and neutrons. The negatively charged particles are electrons. The positively charged particles are protons. Neutrons have no charge.
Strong force is the strongest attractive force. Hence, the force shown in the diagram is strong force. So, the correct option is (C) " strong ".
