Answer
(a) the Cl atom
Work Step by Step
The correct response is (a) the Cl atom.
a) The ionization energy for the chlorine atom represents the energy required to remove an electron from a neutral chlorine atom in its ground state.
b) The Cl⁻ ion already has an extra electron. Its electron affinity would refer to adding another electron to an already negatively charged ion, which is energetically unfavorable due to electron-electron repulsion. This process requires energy, not releases it, and is not equal to the ionization energy of neutral Cl.
c) The Cl⁺ ion is missing an electron. Its electron affinity would refer to adding an electron to a positively charged ion, which is favorable, but the magnitude is not equal to the ionization energy of neutral Cl. These are different species with different energy profiles.
d) Fluorine has a higher electron affinity than chlorine due to its smaller size and greater effective nuclear charge. Therefore, the electron affinity of F is not equal in magnitude to the ionization energy of Cl.
e) This would be correct only if none of the options matched, but option a) is correct, so this choice is invalid.
