The second electron gain enthalpies (in $kJ \ mol^{-1}$) of oxygen and sulphur respectively are

In which of the following processes is the least energy required?

Which of the following statements regarding electron affinity is correct?

Which of the following ions is most unlikely to exist?

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?

Column-$I$ shows the electronic configuration of some elements and Column-$II$ shows the values of electron gain enthalpy. Match these values correctly. Match the electronic configuration with the electron gain enthalpy.

Column-$I$ Electronic Configuration	Column-$II$ Electron Gain Enthalpy / $kJ \ mol^{-1}$
$(A) \ 1s^2 2s^2 2p^6$	$(1) -53$
$(B) \ 1s^2 2s^2 2p^6 3s^1$	$(2) -328$
$(C) \ 1s^2 2s^2 2p^5$	$(3) -141$
$(D) \ 1s^2 2s^2 2p^4$	$(4) +53$