Pauling Electronegativity Chart. Pauling set f arbitrarily at 4.0 (today, the value for f is set to 3.98) and this gives a scale in which the values for all other elements are less than 4 but still with a positive number. The unit used for the electronegativity is pauling.
The periodic table below shows the pauling electronegativity scale. 1 basically, electronegativity of an atom is the relative value of that atom's ability to attract election density toward itself when it bonds to another atom. It shows the different types of chemical bonds formed between atoms based on the electronegativity difference.