AP EAMCET201822 Apr 2018Evening ShiftChemistryClassification of Elements and Periodicity in PropertiesActual
Which of the following represents the correct order of ionic radii?
Options
- AAl ³⁺> Mg ²⁺> Na ⁺> O ²⁻> F ⁻
- BO ²⁻> F ⁻> Na ⁺> Mg ²⁺> Al ³⁺
- CMg ²⁺> Al ³⁺> O ²⁻> F ⁻> Na ⁺
- DO ²⁻> F ⁻> Al ³⁺> Mg ²⁺> Na ⁺
Correct answer
B. O ²⁻> F ⁻> Na ⁺> Mg ²⁺> Al ³⁺
Step-by-step solution
InO ²⁻> F ⁻> Na ⁺> Mg ²⁺> Al ³⁺ All these ions have neon configuration 1 s^2, 2 s^2, 2 p^6 but different nuclear charges, that is why, they are isoelectronic species (different species having the same number and configuration of electrons). To understand the decrease in radius from O ²⁻ to Al ³⁺ . The ionic radii of isoelectronic species increases, with a decrease in magnitudes of nuclear charge. Nuclear charge =+8,+9,+11,+12,+13