Question

The process requiring the absorption of energy is:
A. $N \to N -$
B. $F \to F -$
C. $Cl \to Cl -$
D. $H \to H -$

Answer 1

Initially you must have a knowledge that when an electron is added to an atom, the energy change is exothermic because of the attraction of the electron to the nucleus. So, everything depends on the characteristics of an atom.

Complete step by step solution:
We know that the high stability of the nitrogen molecule contributes considerably to the physical science instability of the many chemical element compounds, during which the bonds, though reasonably sturdy, are so much less therefore than those in molecular nitrogen.
For these reasons, elemental nitrogen seems to hide quite effectively the really reactive nature of its individual atoms. Nitrogen owns a property that it is colourless, scentless gas, that condenses at −195.8 °C to a colourless, mobile liquid
You can see that all the elements can easily gain an electron to form ions. This property is available in all the elements mentioned above i.e., nitrogen, fluorine, chlorine, hydrogen. But, Nitrogen accepts only one electron.
Means every element is ready to absorb more than one electron. So, in case of nitrogen, it releases energy and the value of electron gain enthalpy is negative.
Hence the correct option is A.

Note:
The component exists as $N_2$ molecules, that the bond energy of 226 kilocalories per mole is exceeded solely by that of monoxide, 256 kilocalories per mole. owing to this high bond energy the energy for reaction of molecular chemical element is typically terribly high, inflicting chemical element to be comparatively inert to most reagents underneath normal conditions