The Felkin-Anh model places the group with the highest value for this quantity orthogonal to thecarbonyl. Groups with a high value of this quantity always serve as deactivators of EAS reactions.One form of this quantity is equal to the effective nuclear charge divided by the square of thecovalent radius, while another form expresses it as the arithmetic mean of the (*) ionization energyand the electron affinity. Those are the Allred-Rochow and Mulliken scales. The difference in this quantitybetween two atoms determines whether their bond is ionic or covalent. Fluorine has the highest value forthis quantity with a 4.0 
The Felkin-Anh model places the group with the highest value for this quantity orthogonal to thecarbonyl. Groups with a high value of this quantity always serve as deactivators of EAS reactions.One form of this quantity is equal to the effective nuclear charge divided by the square of thecovalent radius, while another form expresses it as the arithmetic mean of the (*) ionization energyand the electron affinity. Those are the Allred-Rochow and Mulliken scales. The difference in this quantitybetween two atoms determines whether their bond is ionic or covalent. Fluorine has the highest value forthis quantity with a 4.0 on the Pauling scale. For 10 points, name this quantity which describes how well anatom attracts electrons in a bond to itself.
The Felkin-Anh model places the group with the highest value for this quantity orthogonal to thecarbonyl.
electronegativity