Question

Which pollutant tarnishes silver objects





a) Co

b) CO2

c) H2S

d) H2

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Answer 1

Answer:

Archaeological silver and its alloys have relatively high resistance to corrosion products in the atmospheric environment compared to copper and iron objects. But in the presence of humidity and gaseous pollutants―special Sulphur containing pollutants―Silver is susceptible to the tarnishing and corrosion products will be formed. Many corrosion products such as Ag2S, Ag2SO4, AgCl, have been identified on silver objects either in museum environment (displayed in cabinets and stored in depositories) or excavated from the burial environment. Silver objects corrosion in the atmospheric environmental attributed to the water layers on the surface which provide the reaction of the gaseous pollutants such as chloride anions, sulphates, carbonates and Sulphides with metallic surface and lead to the metal dissolution [1] .

Answer 2

Answer:

i don't know about this answer