Give reason:Silver articles when exposed to air gradually turn blackish.

Silver articles turning blackish when exposed to air is due to a chemical reaction called tarnishing. Here's why it happens:

Reaction with Sulfur Compounds: Silver reacts with sulfur compounds present in the air, such as hydrogen sulfide (H2S) or sulfur dioxide (SO2), forming silver sulfide (Ag2S) or silver oxide (Ag2O). These compounds are usually present in small amounts in the atmosphere due to industrial activities, pollution, and natural processes.
Formation of Silver Compounds: The silver sulfide or silver oxide formed on the surface of the silver article is usually black or dark gray in color, which gives the silver its blackish appearance.
Protective Coatings: Pure silver is relatively resistant to corrosion, but most silverware is not pure silver; it's often sterling silver, which is an alloy containing other metals like copper. If the surface of the silver is damaged or the protective coating (such as lacquer or varnish) wears off, it becomes more susceptible to tarnishing.
Presence of Moisture: Tarnishing is accelerated in the presence of moisture because water facilitates the reaction between silver and sulfur compounds in the air.
To prevent tarnishing, silver articles are often coated with a protective layer or stored in airtight containers to minimize exposure to air and moisture. Regular cleaning and maintenance can also help remove tarnish and keep silver items looking shiny and new.