In traditional black-and-white photography, the developed film is chemically "fixed" to prevent the — d and f Block Elements Chemistry Question

💡 Solution & Explanation

Hypo ($Na_2S_2O_3$) acts as a fixing agent. It utilizes the complex-forming ability of transition metals, reacting with the insoluble, unexposed Silver Bromide ($AgBr$) to form the highly water-soluble coordination complex Sodium dithiosulphatoargentate(I), mathematically written as $Na_3[Ag(S_2O_3)_2]$.