Which of the following correctly explains an exception to the expected trend in electron affinities within the periodic table?
1
Beryllium has a positive electron affinity because achieving a full s orbital configuration provides extra stability that repels additional electrons.
2
Fluorine has a less negative electron affinity than chlorine because the addition of an electron to the smaller 2p orbital in fluorine results in greater electron-electron repulsion.
3
Argon has a slightly negative electron affinity owing to its tendency to achieve a stable octet configuration by accepting an electron.
4
Sulfur has a more negative electron affinity than oxygen because sulfur’s larger size and higher principal quantum number reduce electron-electron repulsion when an electron is added.