AP EAPCET 07-Jul-2022 Shift 2 Paper

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As we move across a period, effective nuclear charge
(Zeff)
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
.