What is the absolute highest oxidation state exhibited by any transition element, and which elements — d and f Block Elements Chemistry Question

💡 Solution & Explanation

The maximum oxidation state shown by a metal corresponds to the total number of $(ns + (n-1)d)$ valence electrons. Osmium ($5d^6 6s^2$) and Ruthenium ($4d^6 5s^2$) can utilize all 8 electrons to form $+8$ compounds like $OsO_4$ and $RuO_4$.