In the electrode potential series, only copper have positive value for electrode potential because copper has lower tendency than hydrogen to form ions. So, if standard hydrogen electrode (E_Cell = 0) is connected to copper half-cell, the copper with be relatively less negative or less number of electrons.

$$E_{(C{u^{2 + }}/Cu)}^o$$ = + 0.34 V; $$E_{(F{e^{2 + }}/Fe)}^o$$ = $$-$$ 0.41 V

$$E_{(C{o^{2 + }}/Co)}^o$$ = $$-$$ 0.28 V; $$E_{(Z{n^{2 + }}/Zn)}^o$$ = $$-$$ 0.76 V

$$\therefore$$ Electrode potential of Cu $$E_{(C{u^{2 + }}/Cu)}^o$$ show positive value.