Electron Affinity Calculator
Compare electron affinities of elements in kJ/mol and eV. Predict anion formation tendency.
Compare Elements
Halogens (Highest EA):
Higher Electron Affinity
Cl
Difference: 21.0 kJ/mol
1Cl EA
349 kJ/mol
2F EA
328 kJ/mol
eVCl in eV
3.617 eV
eVF in eV
3.399 eV
Cl
Exothermic
Anion: Favorable
F
Exothermic
Anion: Favorable
Understanding Electron Affinity
Electron affinity (EA) is the energy change when an electron is added to a neutral atom in the gas phase. A positive EA means energy is released (exothermic) when an electron is gained. Halogens have the highest electron affinities because gaining one electron completes their octet.
Noble Gases
EA = 0 (full valence shell)
Nitrogen Anomaly
Negative EA due to half-filled p orbitals