Sterling silver is a mixture of the metals silver and copper. It is used to make jewellery. sometimes sterling silver causes green staining on skin. Which metal do you think is responsible for this?Explain why.

The composition of 925 Sterling Silver lends itself to the occasional green discoloration because of the presence of copper

c is having 4 valence electrons and is bonded to three hydrogens and one sulphur atom, therefore, the number of bond pair is equal to four. as all the valence electrons are used in forming the bonds so, there is no lone pair left on carbon.

s is having 6 valence electrons and is bonded to one other sulfur atom and one carbon atom, therefore, the number of bond pair is equal to 2. as only two valence electrons are used in forming the bonds so, four electrons are left. therefore, two lone pairs are present on s.