Eventually, polyatomic ions generally form which are covalently bonded atoms where the total number of protons is not equal to the whole number of electrons. KCN is used like a photographic fixer in the soaked plate collodion process.The KCN dissolves silver where it hasn't been made insoluble by the developer. https://is-potassium-cyanide-dead93581.blogdosaga.com/30256237/little-known-facts-about-potassium-cyanide-vs-sodium-cyanide