* Sodium (Na): Sodium starts as a neutral atom with one valence electron. It loses this electron to become a positively charged ion called a sodium cation (Na+).
* Chlorine (Cl): Chlorine starts as a neutral atom with seven valence electrons. It gains one electron to complete its outer shell, becoming a negatively charged ion called a chloride anion (Cl-).
The opposite charges of the sodium cation and chloride anion attract each other, forming the ionic compound sodium chloride (NaCl).
