Which element has the highest electronegativity?

Fluorine is known to have the highest electronegativity of all the elements, with a Pauling scale value of approximately 4.0. Electronegativity is a measure of an atom's ability to attract and hold onto electrons when forming chemical bonds. Fluorine's small atomic radius allows it to exert a strong pull on the bonding electrons, making it the most electronegative element.

In the periodic table, electronegativity generally increases across a period from left to right and decreases down a group. Although chlorine and oxygen also have high electronegativities, fluorine surpasses them due to its high effective nuclear charge and minimal atomic size, which leads to a greater attraction for electrons. Nitrogen has a lower electronegativity than all three of these elements, primarily because it is located above them in the same group and has a larger atomic radius compared to fluorine.