Silver articles turn black on exposure to air. This is an example of:
Displacement reaction
Reduction reaction
Oxidation reaction
Redox reaction
Silver articles turn black due to oxidation of silver to silver sulphide.
Silver article become black on prolonged exposure to air this is because
The articles made of silver metal become dark on prolonged exposure to air. This is due to the formation of a layer of its: (a) oxide (b) hydride (c) sulphide (d) carbonate