Chemistry - PERIODIC TABLE Question with Solution | TestHub

A. Fluorine has the highest electronegativity. Chlorine has the highest electron affinity. Helium has the highest ionization energy. This statement is correct.

B. The magnitude of enthalpy change for electron removal from $M_{(g)}$ (ionization energy) and electron addition to $M_{(g)}^{+}$ (electron affinity of $M^{+}$) is the same. This statement is correct.

C. This statement is incorrect. Electron removal from $M_{(g)}$ is ionization energy, and electron addition to $M_{(g)}$ is electron gain enthalpy. These are different processes with different magnitudes.

D. This statement is incorrect. The second ionization energy ($\Delta H_{I{E}_2}$) is always greater than the first ionization energy ($\Delta H_{I{E}_1}$) because removing an electron from a positive ion requires more energy.