what is electronegativity of elements ?please describe in detail .

Electronegativity is the measure of the ability of an atom to attract the electron pair in a covalent bond to itself . In a periodic table , as you go from left to right in a period , the electronegativity increases and it decreases when you move down a group . So most electronegative elements are found at the right hand top corner of the periodic table .

That is the reason why Fluorine is most electronegative element .

Electronegativity is a number and it does not have a unit .