would you mind explaining me what physical significance of tnis paragraph:

"The binding energy of an alkali metal crystal is considerably less than that of an alkali halide crystal: the bond formed by a conduction electron is not very
strong. The interatomic distances are relatively large in the alkali metals because
the kinetic energy of the conduction electrons is lower at large interatomic distances. This leads to weak binding."

Question

would you mind explaining me what physical significance of tnis paragraph: 

"The binding energy of an alkali metal crystal is considerably less than that of an alkali halide crystal: the bond formed by a conduction electron is not very
strong. The interatomic distances are relatively large in the alkali metals because
the kinetic energy of the conduction electrons is lower at large interatomic distances. This leads to weak binding."

anonymous · Answer

Yes, brother.
Summarizing that, it means that within alkali metals, their arrangement consists in positive ions being surround by delocalized electrons. 
As for alkali halides, their arrangement consists in positive ions attracted to NEGATIVE IONS, and remember, an anion or a negative ion is formed when an atom gains an electron, hence differently from the arrangement of an alkali metal, in an halide, there is more attraction between the positive ion and the negative one, because of the excss of 1 more or so electrons and so the intermolecular distance is shorter and hence stronger.
Satisfied?