Nitrogen and fluorine will not form an ionic compound. This is because nitrogen and fluorine are both non-metals. Ionic compounds are formed when a metal reacts with a non-metal. In this case, both nitrogen and fluorine are non-metals, so they will not form an ionic compound. Instead, they will form a covalent compound. Covalent compounds are formed when two non-metals share electrons. In the case of nitrogen and fluorine, they will share three pairs of electrons to form a covalent compound called nitrogen trifluoride.