Chemistry - PERIODIC TABLE Question with Solution | TestHub

The correct statement is (A) because the first ionization energy of $A^{-}(g)$ represents the process $A^{-}(g)\to A(g)+e^{-}$, which is the exact reverse of the electron affinity of $A(g)$, $A(g)+e^{-}\to A^{-}(g)$.

Option (B) is incorrect because the second ionization energy is always greater than the first due to the increased effective nuclear charge holding the remaining electrons more tightly.

Option (C) is incorrect because adding a second electron to a negatively charged O⁻ ion encounters strong inter-electronic repulsion, making the process endothermic.

Option (D) is incorrect because removing an electron from a neutral Lithium atom always requires energy input, meaning it is an endothermic process.