Silver is a precious metal because it does not react easily with oxygen. Silver does, however react with sulfur to form what is called tarnish or silver sulfide (Ag2S). 31 years ago my husband and I exchanged silver wedding bands. On, my 25th anniversary I needed a new band. Over the years the band became thinner until it finally broke in half. Curious, I wondered how much silver I had lost; The ring originally weighed 2.50g, after 25 years the mass was 1.26g. How many silver atoms were lost from the ring over the course of 25 years? help please