What is ionization in the context of chemistry?

Ionization refers to the process in which neutral atoms or molecules gain or lose electrons, resulting in the formation of charged ions. This process is a fundamental concept in chemistry, particularly in understanding how substances interact in various chemical reactions. When an atom loses one or more electrons, it becomes a positively charged ion (cation), while gaining electrons leads to the formation of a negatively charged ion (anion).

Understanding ionization is crucial as it plays a vital role in various phenomena, including the behavior of electrolytes in solutions, the conduction of electricity, and acid-base reactions. This concept provides insight into how substances dissociate in solution and how they participate in chemical bonding and reactions.

The other options relate to different concepts: the creation of nuclear energy pertains to nuclear chemistry, reactions between acids and bases involve neutralization rather than ionization specifically, and the conversion of matter from solid to liquid describes a physical change rather than a chemical change that involves ionization. Thus, option C accurately captures the essence of ionization in chemistry.