The halogens form a homologous series but fluorine differs from the other halogens in many respects which is due to: (I) Small size of F atom and of F~ ion. (ii) High first ionization energy and electronegativity. (iii) Low dissociation energy of F2 molecule as compared to C12 and Br2. (iv) Restriction of the valence shell to an octet.
Due to the small size of the F atom (or F~ ion) there will be a better overlap of orbitals and consequently leads to shorter and stronger bonds with elements other than 0, N and itself. Ionic fluorides have higher lattice energies than the other halides and these values are responsible for the insolubility of the fluorides of Ca, Mg, Ba and Sr in water. Due to the low dissociation energy of fluorine molecule, it is highly reactive. The other halogens react slowly under similar conditions. The fluorides are, however, more stable with respect to dissociation into elements.
Due to the restriction of valence shell to an octet, many fluoro compounds show inertness, e.g. CF4and SF6. Also due to this restriction, F remains restricted to -1 oxidation state.
Fluorine is the only element that combines directly with noble gases like Kr, Xe, and Rn forming their fluorides.
Due to the small size of the F atom (or F~ ion) there will be a better overlap of orbitals and consequently leads to shorter and stronger bonds with elements other than 0, N and itself. Ionic fluorides have higher lattice energies than the other halides and these values are responsible for the insolubility of the fluorides of Ca, Mg, Ba and Sr in water. Due to the low dissociation energy of fluorine molecule, it is highly reactive. The other halogens react slowly under similar conditions. The fluorides are, however, more stable with respect to dissociation into elements.
Due to the restriction of valence shell to an octet, many fluoro compounds show inertness, e.g. CF4and SF6. Also due to this restriction, F remains restricted to -1 oxidation state.
Fluorine is the only element that combines directly with noble gases like Kr, Xe, and Rn forming their fluorides.