Fluorine is a nonmetal. It is located in Group 17 (VIIA) of the periodic table, which is known as the halogens. The halogens are a group of nonmetallic elements that include fluorine, chlorine, bromine, iodine, and astatine.
Fluorine is the most reactive and electronegative of all the elements. It is a pale yellow gas at room temperature and is highly toxic. Due to its high reactivity, fluorine is never found in its elemental form in nature but is instead found in compounds such as fluorite (CaF2) and cryolite (Na3AlF6).
Nonmetals are characterized by their lack of metallic properties such as luster, malleability, and conductivity. Fluorine, like other nonmetals, is a poor conductor of heat and electricity and does not have the shiny appearance of metals. It forms negative ions (anions) by gaining electrons, which is typical behavior for nonmetals.
In summary, fluorine is a nonmetal due to its position in the periodic table, its physical and chemical properties, and its behavior in chemical reactions.