What does the term 'ionization' refer to in the context of matter?

Ionization refers to the process in which neutral atoms or molecules gain or lose electrons, resulting in the formation of charged particles known as ions. When an atom loses one or more electrons, it becomes positively charged (a cation), and when it gains electrons, it becomes negatively charged (an anion). This process is significant in various chemical reactions and can occur through various means, including the application of energy, such as heat or electromagnetic radiation.

Understanding ionization is crucial as it plays a key role in many chemical and physical processes, including electrical conductivity in solutions, chemical bonding, and reactions in plasma states. The other options do not accurately capture the essence of what ionization entails. Losing protons, breaking down compounds, or combining atoms does not pertain to the generation of charged species, which is the fundamental aspect of ionization.