Final answer:
When an atom loses an electron, it becomes ionized and is specifically referred to as a cation, a positively charged particle. This process generally occurs to achieve a more stable electron configuration.
Step-by-step explanation:
When an atom loses an electron, it becomes ionized. Specifically, it becomes a cation, which is a positively charged particle. This is because the atom has more protons than electrons after the electron is lost. Ionic bonds can form when atoms like Na (sodium) lose electrons and become Na+ cations, while other atoms like Cl (chlorine) gain electrons to form anions such as Cl- with a negative charge.
Atoms lose or gain electrons in order to achieve a more stable electron configuration, often aiming for a filled outer shell, which is the most stable arrangement according to the octet rule. For example, metals toward the left side of the periodic table tend to lose electrons to reach this stable state, forming cations in the process.