AP EAMCET20227 Jul 2022Evening ShiftChemistryClassification of Elements and Periodicity in PropertiesActual
In which of the following, elements are correctly arranged in the decreasing order of their second ionisation enthalpies?
Options
- AO > F > N > C
- BN > O > F > C
- CF > O > N > C
- DC > N > O > F
Correct answer
A. O > F > N > C
Step-by-step solution
As we move across a period, effective nuclear charge (Z_ eff ) increases and so do the first ionisation energy, F > O > N > C . But after the removal of 1 electron, the second ionisation potential of oxygen becomes more than that of F as it acquires a half-filled stable electronic configuration. So, the correct order of second ionisation potential is O > F > N > C .