Question

Why do ornaments of gold and silver look dull after using them for sometime?

Answer 1

Because they get exposed to the moisture. Forming an oxide layer over it

Answer 2

Hey mate here is your answer:-

Why do ornaments of gold and silver look dull after using them for sometime?

ans:- because they form a layer of thick oxide which gives it dull nature after some time..

in case of silver it was tarnished by forming a black layer of thick silver sulphide

EQ:- Ag + S2 = Ag2S( black)