Final answer:
The attraction from the nucleus is directly proportional to the number of protons, with the nuclear force providing stability. Coulomb's law and the strong nuclear force are essential in describing this attraction and the binding energy of the nucleus.
Step-by-step explanation:
The attraction from the nucleus is directly proportional to the number of protons within the nucleus. These protons create a positive charge that attracts negatively charged electrons via the electromagnetic force. The attraction between protons and electrons is described by Coulomb's law, where the force is directly proportional to the product of the charges and inversely proportional to the square of the distance between them.
In addition to the electromagnetic force, the strong nuclear force holds the nucleus together, acting as an attractive force between all nucleons (protons and neutrons). This force is necessary because it counters the repulsive Coulomb force among the positively charged protons so that the nucleus does not fly apart. The strength of the nuclear force determines the binding energy and stability of a nucleus, particularly when the nucleus contains many nucleons.