AP EAMCET202123 Aug 2021Morning ShiftChemistryStructure of AtomActual
The ions S ²⁻, Cl ⁻, K ⁺, Ca ²⁺ are isoelectronic. Their ionic radii show
Options
- Aa decrease from S ²⁻ to Cl ⁻ and then increase from K ⁺ to Ca ²⁺
- Ban increase from S ²⁻ to Cl ⁻ and then decrease from K ⁺ to Ca ²⁺
- Ca significant decrease from S ²⁻ to Ca ²⁺
- Da significant increase from S ²⁻ to Ca ²⁺
Correct answer
C. a significant decrease from S ²⁻ to Ca ²⁺
Step-by-step solution
For isoelectronic species, the ionic radii decrease with increase in nuclear charge. So, the cation with greater + ve charge i.e. Ca ²⁺ will have smaller radius and the anion with greater - ve charge i.e. S ²⁻ will have a larger radius. The ionic radii show a significant decrease from S ²⁻ to Ca ²⁺ .