JEE Main202227 Jun 2022Morning ShiftChemistryClassification of Elements and Periodicity in PropertiesActual
Given below are two statements : one is labelled as Assertion and the other is labelled as Reason. Assertion: The ionic radii of O 2 - and Mg 2 + are same. Reason: Both O 2 - and Mg 2 + are isoelectronic species. In the light of the above statements, choose the correct answer from the options given below.
Options
- ABoth Assertion and Reason are true and Reason is the correct explanation of Assertion.
- BBoth Assertion and Reason are true but Reason is not the correct explanation of Assertion.
- CAssertion is true but Reason is false.
- DAssertion is false but Reason is true.
Correct answer
D. Assertion is false but Reason is true.
Step-by-step solution
Both Mg 2 + and O - 2 have 10 electrons each and they are isoelectronic species. But the size of O - 2 is greater than Mg 2 + as size ∝ 1 z e z e   of   Mg 2 + = 12 10 = 1 . 2 z e   of   O - 2 = 8 10 = 0 . 8 z e = Number   of   protons Number   of   electrons