Explain why fluorine always exhibit an oxidation state of -1 ?

Explanation

Fluorine the most electronegative element than other halogens and cannot exhibit any positive oxidation state. Fluorine does not have d-orbital while other halogens have d-orbitals. Therefore fluorine always exhibit an oxidation state of -1 and others in halogen family shows +1, +3, +5 and +7 oxidation states.