Copper (Cu) = 29 3d104s1
Silver (Ag) = 47 4d105s1
Gold (Au) = 79 5d106s1
General configuration is (n -1) d10ns1 and being to d-block of periodic table i.e. coinage metals are transition metals.
Coinage metals have characteristics color.
Copper → red
Silver → white
Gold → yellow
They show common oxidation state of +1. Besides +1, copper has +2 and gold has +3 O.S.
They lie at the lower part of electrochemical series. So they are least reactive metal and are found in native state