* Sodium (Na) loses an electron: Sodium atoms are in Group 1 of the periodic table, meaning they have one valence electron. They tend to lose this electron to achieve a stable electron configuration like that of the noble gas neon. This results in a positively charged sodium ion (Na⁺).

* Sulfur (S) gains two electrons: Sulfur atoms are in Group 16 of the periodic table, meaning they have six valence electrons. They gain two electrons to achieve a stable electron configuration like that of the noble gas argon. This results in a negatively charged sulfide ion (S²⁻).

* Ionic bond formation: The oppositely charged sodium ions (Na⁺) and sulfide ions (S²⁻) are attracted to each other through electrostatic forces. This attraction forms an ionic bond, creating the compound sodium sulfide (Na₂S).

Key points:

* Electrostatic attraction: The strong attraction between the oppositely charged ions holds the compound together.

* Neutral compound: The overall charge of the compound is neutral because the positive charges from the two sodium ions balance out the negative charge from the sulfide ion.

* Formula unit: The formula unit Na₂S represents the simplest ratio of ions in the compound.

Let me know if you'd like more details on ionic bonding!