3, point, space In compounds: fluorine is assigned a − 1 −1 − 1 −, 1 oxidation number; oxygen is usually assigned a − 2 −2 − 2 −, 2 oxidation number (except in peroxide compounds where it is − 1 −1 − 1 −, 1, and in binary compounds with fluorine where it is positive); and hydrogen is usually assigned a + 1 +1 + 1 plus, 1 oxidation number except when it exists as the hydride ion, H − \text{H}^− H − start text, H, end text, start superscript, −, end superscript What is the oxidation number for the silver ion in tarnish? Source(s): oxidation number silver ion tarnish: https://biturl.im/4LqVH. 0 0 0. Login to reply the answers Post; Still have questions? Get your answers by asking now. Ask Question + 100. Join Yahoo Answers and get 100 points today. That explains silver's +1 oxidation state. Silver readily forms binary molecules with the Halogens. Another very common silver compound is Ag2S, silver sulfide. This is a dark-to-black compound appearing on silver items as tarnish. It can be removed with metal polishing cloths, but that also removes some silver.