The amount of energy released on the addition of an electron in the outermost shell of an atom is called:

Which will have the maximum value of electron affinity among $O^x, O^y$ and $O^z$ ($x, y$ and $z$ are $0, -1$ and $-2$ respectively)?

Select the process in which the least enthalpy change is associated:

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

The set containing the elements with positive electron gain enthalpies is

Which one of the following arrangements represents the correct order of least negative to most negative electron gain enthalpy for $C, Ca, Al, F$ and $O$?