3.7—Reasons for the trends in ionic radii down a group in the Periodic Table, and for a set of isoelectronic ions

Understand reasons for the trends in ionic radii down a group in the Periodic Table, and for a set of isoelectronic ions, including N3− to Al3+.

Use —reasons for the trends in ionic radii down a group in the periodic table, and for a set of isoelectronic ions to connect the rule to the data and decision in the question.

This matters because —reasons for the trends in ionic radii down a group in the periodic table, and for a set of isoelectronic ions determines what can be inferred or chosen; begin with the stated conditions and keep the conclusion tied to the evidence.

Example: apply —reasons for the trends in ionic radii down a group in the periodic table, and for a set of isoelectronic ions to one small, clearly defined case, show the key step or comparison, and explain the result in words.

Boundary: —Reasons for the trends in ionic radii down a group in the Periodic Table, and for a set of isoelectronic ions is not a universal recommendation. Check the syllabus scope, assumptions, units and the limits of the evidence before generalising.