conductivities of d-block metals
Hi, I am doing a bit of research on conductivities of d-block metals (just for fun, really). The questions I have got are the following
1)I know that d-electrons of Nth shell are on averge held much closer to nucleus than s- and p- electrons of (N+1)st shell. Does it mean that they can form metal-metal bonds (in the solid) which are localised? That would account for lattice enthalpies of most d-block metals being so much greater than those of p-block metals without a correponding increase in conductivity.
2)One would expect that the energy gap between the full band (where the s-elestrons reside in the ground state) and the conduction band in Scandium should be of a similar magnitude to that in Ca, however their conductivities are widely different. In fact, Sc could easily have it's d-electron promoted to the p-shell, so it's conductivity should resemble that of Al (which is far greater). Is it perhaps due to increased electron-electron repulsion (due to the addition of one extra electron)?
3)Conductivity of Chromium is higher than conductivities of the preceding elements in the block. Yet it's d-shell is half-full with unpaired electrons occupying both bonding and antibonding orbitals. So the only way it can conduct is by using it's s-electron. Does it mean that preceding elements used onle their s-electrons to conduct as well?
4)Mn, Fe, Co and Ni behave well. But why is the conductivity of Cu so high? It should not be able to use it's d-electrons for that. Yet it outdoes K, which also has an unpaired s-electron. Is that because of smaller metallic radius of Cu (so number of conducting electrons per unit volume is greater)?
5)Conductivities in the second row are greater than conductivities in the first row. Does this have anything to do with lanthanide contraction?