The second electron gain enthalpy of an element:

Which one of the following statements is incorrect?

The increasing order of electron affinity for the given electronic configurations of elements is:
$I. 1s^2 2s^2 2p^6 3s^2 3p^5$
$II. 1s^2 2s^2 2p^3$
$III. 1s^2 2s^2 2p^5$
$IV. 1s^2 2s^2 2p^6 3s^1$

Which of the given atoms has the greatest electron affinity?

When an electron is added to elements of group $16$ and $17$ in $n = 2$ and $n = 3$ shells,which case experiences less electron-electron repulsion and why?

Arrange $N$,$S$,$O$ and $F$ in order of decreasing electron gain enthalpy.