Imat 2021 question 45

which of the following equations is associated with the first electron affinity of chlorine?

A. Cl(g) + e⁻ ---- Cl⁻(g)

B. Cl(g) ----- Cl⁻ + e⁻

C. Cl2(g) + 2e⁻ ----- 2Cl⁻(g)

D. 2Cl⁻(g) - 2e⁻ ---- Cl2(g)

E. Cl⁻(g) + e⁻ ---- Cl(g)

Hi everyone!
The answer is A, why isn’t it C? i thought chlorine gas occurs naturally as a diatomic molecule. So do we consider electron affinity always for an individual atom and never a molecule?

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I totally understand you actually I used to be confused too but if you know the definition of the first electron affinity is the energy released when 1 MOLE of gaseous ATOM each acquire an electron to form 1 mole of gaseous 1- ions. They mean the atom and not the molecule. Hope it makes sense! :))