* Sodium (Na) is a metal and readily loses one electron to achieve a stable electron configuration.

* Oxygen (O) is a nonmetal and readily gains two electrons to achieve a stable electron configuration.

When sodium and oxygen react, sodium atoms lose one electron each, becoming positively charged sodium ions (Na⁺). Oxygen atoms gain two electrons each, becoming negatively charged oxide ions (O²⁻).

The strong electrostatic attraction between these oppositely charged ions forms the ionic compound sodium oxide. The formula Na₂O reflects the need for two sodium ions to balance the charge of one oxide ion.