Ionization occurs when a neutral atom acquires charge by gaining or losing what?

Ionization occurs when a neutral atom gains or loses electrons. Electrons are the negatively charged particles that surround the nucleus of an atom, and their presence or absence determines the overall charge of the atom. When an atom gains one or more electrons, it becomes negatively charged, forming an anion. Conversely, when it loses electrons, it becomes positively charged, forming a cation.

This process is fundamental to many chemical reactions and physical processes, as the charge difference that results from the gain or loss of electrons leads to interactions between atoms and molecules. In contrast, protons and neutrons, which are located within the nucleus, do not typically participate in ionization under normal conditions, and changes in the nucleus itself (such as the alteration of nuclei) are more associated with radioactive decay or nuclear reactions rather than the ionization process.