Which metal in the first series of transition metals exhibits + 1 oxidation state most frequently and why?

cbse
dandf-blockelements

#1

Electronic configuration of Cu = [Ar] . When copper atom loses 1 electron, it exhibits +1 oxidation state and forms $Cu^{+}$ ion with stable $3{{d}^{10}}$ configuration. So, copper metal in the first transition series tends to have +1 oxidation state to achieve a stable configuration.