Fluorine has seven electrons in its outermost shell. it will most likely try to join an atom with

F (Fluorine) has (8-1 = 7) electrons in outer most shell and so, it will try to bond with an atom which has only 1 electron in its outer most shell.

Explanation:

According to Octet rule, most of the atoms are said to be stable if it has 8 electrons in its outermost shell. As already said, Fluorine atom has 7 electrons while it requires 1 more electron to attain stability.

Hence, F atom will try to join another atom with only one electron in outer shell, like H, Li and Na.

Its either with itself to become fluoride Fl2 or with an alkali metal (elements in group 1) to achieve a stable electronic configuration or octet structure