Question

The process requiring absorption of energy is:
A. \[N\to {{N}^{-}}\]
B. \[F\to {{F}^{-}}\]
C. \[Cl\to C{{l}^{-}}\]
D. \[H\to {{H}^{-}}\]

Answer 1

Hint: Some atoms need some amount of energy to accept electrons. The amount of energy required by the atoms to accept electrons is called absorption energy. Without the need of absorption energy maximum atoms will not accept electrons.


Complete step by step answer:
- We have to find which atom or element is going to absorb energy when accepting electrons.
- Coming to option A, \[N\to {{N}^{-}}\].
- In option A, nitrogen is going to accept electrons to form (\[{{N}^{-}}\]).
- The electronic configuration of nitrogen is \[1{{s}^{2}}2{{s}^{2}}2{{p}^{3}}\].
- Nitrogen has half-filled electrons in its electronic configuration.
- We know that an atom is very stable if the atom has half-filled or completely filled electrons.
- So, it needs more absorption energy to add electrons to nitrogen atoms.
- Coming to option B,\[F\to {{F}^{-}}\].
- In the above equation Fluorine accepts one electron and converts into fluoride ions.
- The atomic number of fluorine is 9. To get octet electronic configuration fluorine accepts one electron without the need of absorption of energy. Therefore for\[F\to {{F}^{-}}\]reaction, the absorption energy is too less.
- Coming to option C,\[Cl\to C{{l}^{-}}\].
- To get octet electronic configuration chlorine accepts one electron without the need of absorption of energy. Therefore for\[Cl\to C{{l}^{-}}\]reaction, the absorption energy is very less.
- Coming to option D,\[H\to {{H}^{-}}\].
- Hydrogen atoms have one electron in its electronic configuration. Therefore hydrogen accepts one electron from other atoms to fill the 1s orbital. Accepting an electron by hydrogen does not need a lot of absorption energy. Therefore for\[H\to {{H}^{-}}\] reaction, the absorption energy is very less.
- Therefore the reaction \[N\to {{N}^{-}}\]needs more absorption energy to add electrons to nitrogen.

- So, the correct option is A.


Note: In a chemical reaction if energy is going to be absorbed by the atom or molecule then it is called endothermic reaction and in a chemical reaction if energy is going to be released by the atom or molecule then it is called exothermic reaction.