Which oxide of a group 17 element is the most stable in its highest oxidation state?
Stability of group 17 oxides in high oxidation states increases down the group. I₂O₅ (I, +5) is the most stable, unlike F₂O, Cl₂O₇, or BrO₃.
Ref: NCERT Class 11 Chemistry > Chapter 3: Classification of Elements and Periodicity in Properties > Topic: Modern Periodic Law and Present Form - Long Form Periodic Table