AP EAMCET201726 Apr 2017Morning ShiftChemistryStructure of AtomActual
Assertion (A) : Na ⁺ and Mg ²⁺ ions are isoelectronic but the ionic radius of Na ⁺ is greater than that of Mg ²⁺ . Reason (R) : The effective nuclear charge of Na ⁺ ion is less than that of Mg ²⁺ ion.
Options
- ABoth (A) and (R) are correct but (R) is not the correct explanation of (A).
- BBoth (A) and (R) are correct and (R) is correct explanation of (A).
- C(A) is not correct but (R) is correct.
- D(A) is correct but (R) is not correct.
Correct answer
B. Both (A) and (R) are correct and (R) is correct explanation of (A).
Step-by-step solution
Na ⁺ and Mg ²⁺ are isoelectrionic species having 10 e⁻ each. But Mg ²⁺ has 12 protons while Na ⁺ has 11 protons. Hence effective nuclear charge is greater in case of Mg ²⁺ . ionic radius 1 effective nuclear charge