Question

What is the unit of measurement used for electronegativity?

Answer 1

Hint: Electronegativity is the property of an element to attract the shared pair of electrons towards itself. It is measured on various scales like the Pauling scale, and Mullikan scale. Pauling scale is the most widely used to measure electronegativity of any element. Electronegativity increases as we go from left to right in a periodic table.

Complete answer:
Electronegativity of any element is its ability to attract the shared pair of electrons of other elements in a molecule towards itself and form bonds. This electronegativity of elements increases as we move from left to right in a period. This means that metals, which are at extreme left are less electronegative, while non metals (till group 17) that are at the right in a period are more electronegative. This happens as metals lose electrons to form compounds, while non – metals accept electrons, meaning they can attract electrons by accepting, creating partial negative charge on the electronegative atom.
Electronegativity is the property of elements, it has no measurable numerical value. therefore it has no units.
Electronegativity of elements is ranked through various scales designed by scientists. Among them, the Pauling scale is widely used. According to Pauling scale, Fluorine is assigned a value of 4 which is the highest value of electronegativity. So, fluorine is the most electronegative element.
Hence, electronegativity has no unit as it has no quantity. It is measured on a scale, called Pauling scale.

Note:
The electronegativity values are not constant and depend on the oxidation state of the metal, greater oxidation state means more electronegativity. Also the attached atoms in a molecule decide the electronegativity. Effect of hybridization on electronegativity is in the order, $sp>s{p}^2>s{p}^3$, this is the order of carbon atoms.