MENDELIEV'S PERIODIC TABLE and SUPERCONDUCTIVITY:Here it is pointed out that,like chemical properties,elemental metals in the same column of the table and in one headed by a nonmagnetic metal typically have similar Tc's.

In the first and second columns of the periodic table, headed by lithium and beryllium, none of the 5 alkali metals or 5 alkaline earth metals
is a superconductor(see the table on p.356 of the 5th edition of Kittel).Of the many rare earth metals in the third column only lanthanum is a superconductor. In the fourth and fifth columns,headed by titanium and vanadium,all three metals in each column is a superconductor. In the fourth column Tc's vary between .37 K and .56 K. In the fifth column Tc's are an order of magnitude higher with niobium having the highest at 9.2 K. Skipping over the next few columns headed by magnetic metals we arrive at the column of the precious metals. None of the these ls a superconductor. Once again in the next column headed by zinc all three elemental metals are superconductors. .Mercury's Tc of 4.2K is higher than Zn(.8K) and Cd(.6K) perhaps due to it's low melting point(-40 C).This brings us to the last column headed by a metal in this case aluminum. All 4 elemental metals are superconductors. Ga(1.1K) has the lowest Tc while In(3.4K) has the highest. Of the 5 light elemental metals in the top two rows of the periodic table only aluminum is superconducting! Why?In time will it become possible to calculate its Tc accurately from first principles?