Explain, with reference to electron structure, why the ionic radii of period 4 ions \( Ca^{2+} \), \( Co^{2+} \) and \( Br^{-} \) are different. Use section 10 of the data booklet.
Explain, with reference to electron structure, why the ionic radii of period 4 ions \( Ca^{2+} \), \( Co^{2+} \) and \( Br^{-} \) are different. Use section 10 of the data booklet.