Question

Which of the following processes involves absorption of energy?
(A) $S(g)+{{e}^{-}}\to {{S}^{-}}(g)$
(B) ${{S}^{-}}+{{e}^{-}}\to {{S}^{-2}}(g)$
(C) $Cl(g)+{{e}^{-}}\to C{{l}^{-}}(g)$
(D) none of these

Answer 1

Hint: The system can have only certain energies and not a continuation of energies is observed as energy is quantized in some systems. Discrete lumps of energy will take place in some forms of energy transfer. The indication of energy levels being quantized in atoms and molecules from the lines in the atomic spectra of electromagnetic radiation emissions belongs to individual atoms and molecules.

Complete step by step answer:
When a substance absorbs energy then the spectrum of emitted radiation is called an emission spectrum. Atoms, molecules, or ions are excited by absorbed radiation.
When a neutral electronegative atom gains an electron which releases energy. The anion which is formed after releasing energy, gains electrons by absorbing energy, due to the repulsion of between the negatively charged ion and the additional electron.
(A) $S(g)+{{e}^{-}}\to {{S}^{-}}(g)$. In this case, sulfur is a neutral electronegativity atom that absorbs electrons and releases energy. So, this process does not involve the absorption of energy.

(B) ${{S}^{-}}+{{e}^{-}}\to {{S}^{-2}}(g)$. In this case, the negatively charged species of sulfur gains electrons by absorption of energy. This is the process that involves the absorption of energy.

(C) $Cl(g)+{{e}^{-}}\to C{{l}^{-}}(g)$, In this case, chlorine is neutral electronegativity atom absorbed electron and releases energy. So, this process does not involve the absorption of energy.
So, the correct answer is “Option B”.

Note: The spectroscopic methods are used to analyze the minerals of elements like rubidium (Rb), cesium (Cs), thallium (Tl), indium (In), and Gallium (Ga) which are also discovered by these methods. The characteristics of lines in atomic spectra because they emitted radiation used to analyze to identify unknown atoms.