Consider the set of isoelectronic atoms and ions A^2-, B^-, C, D⁺, and E²⁺. Which arrangement of relative radii is correct?

Question

Quizplus · Accepted Answer

Isoelectronic species have the same number of electrons, but they can have different numbers of protons. The effective nuclear charge (Zeff) and the number of shells determine the radius of an atom/ion. Among the given isoelectronic species, the one with the highest Zeff will have the smallest radius because the positively charged nucleus pulls the electrons closer. Among the given options, the arrangement that satisfies this trend is A. Specifically, A^2- has the most protons and highest Zeff, so it has the smallest radius. The trend continues with decreasing Zeff as we move down the list, which corresponds to increasing radii.

Consider the Set of Isoelectronic Atoms and Ions A2-, B-

Consider the Set of Isoelectronic Atoms and Ions A^2-, B^-