A chemist is investigating a set of five ions that each contain ten electrons

CHEMISTRY · Multi-part · A Level · Chemistry · Periodicity and periodic trends · Periodicity and periodic trends

Problem

A chemist is investigating a set of five ions that each contain ten electrons. The ions are listed below in no particular order:

N^{3-}

O^{2-}

F^{-}

Na^{+}

Mg^{2+}

Assume all ions are in their ground state and are not interacting with any other species. (a) Identify the ion in the set that has the largest ionic radius. Provide a detailed justification that references the relevant periodic property or properties. (b) Rank the five ions from smallest to largest ionic radius. In your explanation, clearly relate each step in the ordering to the underlying factors that determine ionic size. (c) Predict qualitatively how the ionic radius of

Al^{3+}

would compare with the radii of the ions listed above, and explain the reasoning for your prediction.

Related theory

Atomic and ionic radii
Classification of Elements and Periodicity in Properties
Periodic Trends in Physical Properties

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