what kind of bond is formed when lithium and fluorine combine to form lithium fluoride?

When lithium and fluorine combine to form lithium fluoride, they form an ionic bond.

In simple terms, lithium (a metal) loses one electron to become a positively charged Li⁺ ion, and fluorine (a nonmetal) gains that electron to become a negatively charged F⁻ ion. The strong electrostatic attraction between these oppositely charged ions is what we call an ionic bond, giving the compound lithium fluoride (LiF).