Final answer:
A neutral atom becomes an ion with a positive or negative charge when it gains or loses electrons, respectively, but its element type remains the same. Adding or removing neutrons results in different isotopes of the same element without affecting its charge. A neutral atom's atomic number determines its electrical neutrality by matching the number of protons to the number of electrons.
Step-by-step explanation:
When a neutral atom gains or loses electrons, it forms an ion, changing its charge but not its element. If a neutral atom, like sodium, loses an electron, it becomes a positively charged ion (Na+). On the other hand, if a neutral atom, such as chlorine, gains an electron, it becomes a negatively charged ion (Cl-). Adding or removing neutrons creates isotopes, which are atoms of the same element with varying numbers of neutrons, having no effect on the atom's electrical charge or chemical behavior.
The atomic number of an element is defined by its number of protons, which also indicates how many electrons a neutral atom of that element contains. Changes in the number of protons transform the atom into a different element altogether. However, in a neutral atom, the number of electrons always equals the atomic number, maintaining a balance between the positive and negative charges.