Answer:
Variable valency of gold
Different sizes of gold particles
Different concentrations of gold particles
Presence of impurities produced by different methodsVariable valency of gold
Different sizes of gold particles
Different concentrations of gold particles
Presence of impurities produced by different methodsVariable valency of gold
Different sizes of gold particles
Different concentrations of gold particles
Presence of impurities produced by different methodsVariable valency of gold
Different sizes of gold particles
Different concentrations of gold particles
Presence of impurities produced by different methods