What is the difference between #"electron affinity"#, and #"electronegativity"#?
Well one is a measured property..........
Electron affinity is the energy associated with the reaction:
And of course, this energy may be measured.
Electronegativity is a more contrived parameter, and is conceived to be the ability of an atom involved in a chemical bond to polarize electron density towards itself. To make this determination, the various scales of electronegativity utilize ionization energies and atomization energies.
And this spells out the second difference. Electronegativity interrogates molecular properties, and electron affinity is an ATOMIC property.
And finally the third difference; electronegativity relies on arbitrary scales, whose use may be inappropriate in certain scenarios, whereas electron affinities have definite units of
Both concepts are hard to differentiate, and one relies on the other......