Question

Silver metal does not combine easily with oxygen but silver jewellery transition after sometime how

Answer 1

It is because silver because silver oxidises.
-) Ag + O2 -> AgO

Answer 2

Silver tarnishes from the interaction with sulfides in the air. First the tarnish will take on a golden hue and eventually it will turn the piece black. This is a natural process. Higher sulfide levels are associated with humidity and air pollution.So without reacting with oxygen it tarnishes