Final answer:
Noble gases do not have electronegativity values because they are chemically inert with a full valence shell, rarely forming bonds with other atoms. Pauling's electronegativity scale does not assign values to noble gases, as they do not fit the usual bonding and polarity models.
Step-by-step explanation:
The last family on the periodic table, the noble gases, does not have any values for electronegativity because these elements typically do not form bonds with other atoms. Electronegativity is the measure of an atom's ability to attract and hold onto electrons when it is part of a compound. Noble gases already have a complete valence shell, making them chemically inert and stable in their neutral form.
Since electronegativity is a concept that helps predict the polarity of bonds between atoms in molecules, and noble gases rarely form such bonds, Pauling's electronegativity values are not assigned to these elements. Even though compounds like XeO₂ exist, they are exceptions and are formed under extreme conditions, which do not alter the general trend in electronegativity across the periodic table. As a result, the noble gases are excluded from electronegativity scales.