The correct answer is c) electron. When the number of electrons in an atom changes, an ion is produced. An atom becomes an ion when it gains or loses electrons. If an atom gains one or more electrons, it becomes a negatively charged ion, or an anion. On the other hand, if an atom loses one or more electrons, it becomes a positively charged ion, or a cation. Consequently, changing the number of electrons in an atom directly affects the formation of ions.
