Two fluorine atoms form one covalent bond between them.

Here's why:

* Fluorine's Electron Configuration: Fluorine has 7 electrons in its outer shell, needing one more to complete its octet (8 electrons).

* Sharing Electrons: To achieve a stable configuration, two fluorine atoms share one electron each, forming a single covalent bond. This shared pair of electrons now counts towards both atoms' octets.