Fluorine is a name for the gas and the ion without the extra electron that fluorine will rip from any other (non-noble gas) element. F0 or F2 Fluoride is the name for the fluorine negatively charged ion. F-
Fluorine can be in all 3 states of matter, however, at room temperature and normal pressure (STP) Fluorine is always in the gas form. It is a colourless (or pale yellow) gas existing as a diatomic molecules F2.