KentuckyFC writes: The great power of Mendeleev's periodic table was that it allowed him to predict the properties of undiscovered elements. But can this arrangement be improved? Two new representations of the periodic table attempt to do just that. The first uses a new graphical representation that shows the relative sizes of atoms as well as their groups and periods. The other uses the same kind of group theoretical approach that particle physicists developed to classify particles by their symmetries (abstract). That helped particle physicists predict the existence of new particles but may have limited utility for chemists who seem to have discovered (or predicted) all the elements they need already.