NEET2010Chemistryp Block Elements (Group 15, 16, 17 & 18)Actual
Assertion : Helium has the highest value of ionisation energy among all the elements known. Reason : Helium has the highest value of electron affinity among all the elements known.
Options
- AIf both assertion and reason are true and reason is the correct explanation of assertion
- BIf both assertion and reason are true but reason is not the correct explanation of assertion
- CIf assertion is true but reason is false
- DIf both assertion and reason are false.
Correct answer
C. If assertion is true but reason is false
Step-by-step solution
He contains fully filled 1 s^2 orbital which has more penetrating effect and is very close to the nucleus and hence has higher value of ionisation energy.