Final answer:
Fluorine has the greatest electron affinity among the provided options, which are arsenic, sulfur, and fluorine, due to its high electronegativity and its tendency to gain one electron to achieve a stable configuration.
Step-by-step explanation:
The atom with the greatest electron affinity (EA) among arsenic (As), sulfur (S), and fluorine (F) is fluorine. Electron affinity is the energy change that occurs when an electron is added to a gaseous atom, and atoms with high electron affinity release more energy when they gain an electron, thus having a more negative value. Fluorine has an EA of -322 kJ/mol which is high compared to most other elements due to its high electronegativity and its desire to gain one electron to achieve a stable noble gas configuration. Chlorine has the highest EA in the periodic table at -348 kJ/mol, but of the options provided, fluorine is the closest in terms of high electron affinity.