question_answer

  \[P{{F}_{5}}\] is known but \[N{{F}_{5}}\] is not known. Discuss.

Answer:

                                Nitrogen does not have any \[2d\] orbitals in its valence shell. Therefore, it cannot extend its covalency upto five. But incase of phosphorus, vacant \[3d\] orbitals are present. An electron can be promoted from \[3s\] to \[3d\] orbital. As a result, phosphorus can extend its covalency upto five and a molecule of \[P{{F}_{5}}\] can exist.