Question

what are isoelectronic and isostructural species? those with same no of electrons or those with same no of valence electrons?

Answer 1

Explanation:

Isoelectronic species are the species which have the same number of electrons around them. For Example: $F^-,Ne\text{ and }Na^+$ have the same number of electrons around them which are 10 electrons.

Isostructural species are defined as the species which have same shape and hybridization. These species have same number of valence electrons. For Example: $CH_4\text{ and }NH_4^+$ have same number of electrons and both of them have the same shape which is tetrahedral. Hence, these two compounds are isoelectronic as well as isostructural species.