Isoelectronic Posted on 1st December 20155th October 2020 by ThePD (The Project Definition) Isoelectronic is chemical species that have the same number of valence electrons and the same structure, but differ in some of the elements involved. Click to share on Twitter (Opens in new window)Click to share on Facebook (Opens in new window)Click to share on LinkedIn (Opens in new window) Related Posted in Substance and tagged chemical. ThePD (The Project Definition) ThePD has been developing the Preferred Project Definitions based on the actual project execution and operation experiences and knowledge with the Project Language, and sharing with you daily basis.