Here's why:
* Sodium (Na) is a metal and tends to lose one electron to achieve a stable electron configuration. This makes it a positively charged ion (Na+).
* Fluorine (F) is a nonmetal and tends to gain one electron to achieve a stable electron configuration. This makes it a negatively charged ion (F-).
* Ionic bonds form when a metal atom donates an electron to a nonmetal atom. The electrostatic attraction between the oppositely charged ions holds them together.
Therefore, the bond between sodium and fluorine in sodium fluoride (NaF), the compound used for fluoridating drinking water, is an ionic bond.
