Chlorine electron affinity, enthalpy of dissociation of the X molecule (X = Cl, Br, I), ionic radius, and X–X bond length. (Fluorine is anomalous due to its small size.) All four stable halogens experience intermolecular van der Waals forces of attraction, and their strength increases together with the number of electrons among all homonuclear diatomic halogen molecules. Thus, the melting and boiling points of chlorine are intermediate between those of fluorine and bromine: chlorine melts at −101.0 °C and boils at −34.0 °C. As a result of the increasing molecular weight of the halogens down the group, the density and heats
Fluorine perchlorate and perchlorates, it needs to be handled with extreme caution. FClO is a strong oxidant and it reacts with iodide ion: FClO can also react with tetrafluoroethylene: It may be a radical addition reaction. Fluorine perchlorate Perchloryl Hypofluorite is the rarely encountered chemical compound of fluorine, chlorine, and oxygen with the chemical formula or . It is an extremely unstable gas that explodes spontaneously and has a penetrating odor. One synthesis uses fluorine and perchloric acid, though the action of ClF on water is another method. Another method of synthesis involves the thermal decomposition of tetrafluoroammonium perchlorate, , which yields