Question

what is meat of isoelectronic​

Answer 1

Atoms and ions that have the same electron configuration are said to be isoelectronic. Examples of isoelectronic species are N3–, O2–, F–, Ne, Na+, Mg2+, and Al3+ (1s22s22p6). For atoms or ions that are isoelectronic, the number of protons determines the size.

Answer 2

having the same numbers of electrons or the same electronic structure.