What type of bond forms between lithium and fluorine?
Lithium is an alkali metal and form an ionic bond by donating an electron.
Fluorine is a halogen and forms ionic bonds by accepting an electron.
Diagramming the formation of an ionic bond between lithium and fluorine looks exactly like the diagrammed bond between sodium and chlorine in the video below. Lithium behaves just like the sodium (Na) and fluorine will act like the chlorine (Cl).
The electronegativity difference between lithium (0.98) and fluorine (3.98) is 3 Pauling units. Depending on who you ask, when elements have a difference of 1.7 (or 2.0) Pauling units the bond is classified as ionic. This bond would be classified as ionic no matter who you were to ask.
Hope this helps!