Noble gases group trends

True, except for the group 18 noble gas elements, which are not assigned an electronegativity number. The trend is that electronegativity decreases with an increasing number of shells down any one atomic group (vertical column) of the periodic table. 

The optical spectra of Ni, Pd and Pt in noble gas matrices have been measured in order to search for complexes of these Group VIII ligands. Changes in the energy levels of the matrix isolated atoms occur because of a weak metal interaction. For platinum the frequency shifts follow the trend Xe > Ar > Kr, but whether this interaction is described as a Van der Waals interaction or a weak coordinate bond is open to speculation.1976... 

Starting with Group 15, in which atoms assume stable noble-gas configmations by gaining three electrons, anions are more common than cations. Anionic radii decrease across each period for the elements in Groups 15-18. The reasons for this trend are the same as the reasons that cationic radii decrease from left to right across a period. 

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