Figure shows that the differences in φ b of 0.7 eV to 0.9 eV between gold and silver electrodes are close to the difference of 0.85 eV between the work functions of the Au(111) (5.31 eV) and Ag(111) (4.46 eV) surfaces. This similarity strongly suggests that the change in φ b between gold and silver occurs primarily due to the change in the Fermi energy of the metal. In contrast, the similar differences in φ b of between gold and copper electrodes of 0.7 eV to 0.9 eV are much greater than the difference of 0.37 eV between the work functions of the Au(111) (5.31 eV) and Cu(111) (4.94 eV) surfaces. These subtleties demonstrate how conductance trends that depend on the atomistic nature and orbital overlaps at the interface can deviate from expected periodic trends derived from macroscopic properties, such as the work function. To relate the mechanical stability to the variation in conductance with inter-electrode distance (a), we report the conductance gradients of the junctions in Fig. (b), which were calculated from the linear change in conductance due to small de- viations in a from the optimal inter-tip distance. Importantly, the negative conductance gradients of all our junctions indicate that the conductance of each junction decreases as it is stretched, which we found was primarily due to the increase in the tunneling distance, a rather than an increase in φ b . This negative slope is consistent with previous experimental results on BDTgold junctions by Tao and coworkers. Examination of the electrical (conductance and conductance gradient) and mechanical (binding energy and binding force constant) properties shows that barring the larger k b values of BDA-atop-copper and BDT-FCC-copper, junctions built with gold electrodes conduct and bind more strongly than the corresponding junctions with silver and copper electrodes. However, the conductance with gold electrodes is much more sensitive to pulling of the junction and decreases more rapidly with a as compared to silver and copper electrodes.