Transition metals and their salts play foundational roles in traditional photographic processes. Whi — d and f Block Elements Chemistry Question

💡 Solution & Explanation

(A) is correct; $AgBr$ is the primary light-sensitive compound in photographic films. (B) is correct; hypo ($Na_2S_2O_3$) acts as a fixer by complexing and washing away unexposed $AgBr$ as $[Ag(S_2O_3)_2]^{3-}$. (C) is correct; $AuCl_3$ is classically used in photography for toning (replacing silver with gold to shift image tone and increase archival stability). (D) is incorrect; developers are typically organic reducing agents like hydroquinone (quinol), not $FeCl_3$.