BITSAT2013ChemistryClassification of Elements and Periodicity in PropertiesActual
The ions O ²⁻, F ⁻, Na ⁺, Mg ²⁺ and Al ³⁺ are isoelectronic. Their ionic radii show:
Options
- AA decrease from O ²⁻ to F ⁻ and then increase from Na ⁺ to Al ³⁺
- BA significant increase from O ²⁻ to Al ³⁺
- CA significant decrease from O ²⁻ to Al ³⁺
- DAn increase from O ²⁻ to F ⁻ and then decrease from Na ⁺ to Al ³⁺
Correct answer
C. A significant decrease from O ²⁻ to Al ³⁺
Step-by-step solution
Amongst isoelectronic species, ionic radii of anion is more than that of cations. Further size of anion increase with increase in -ve charge and size of cation decrease with increase in + ve charge. Hence ionic radii decreases from O ⁻ to Al ³⁺