Use these when teaching the young 'uns about various trends among the elements! The higher the box, the bigger the relative value (biggest = 3 cm high). OOPS! Density was incorrect -- fixed now, at least the individual STL download is fixed -- the ZIP version of density still looks like it must be melting point, and I'm too lazy and have too slow of a connection to fix it! Sorry for the inconvenience!I used openscad to create this, using data found on various websites (webelements among others.) If data wasn't known (see: Darmstadtium) the value was simply left at zero. One openscad file is included, in case you want to tediously tweak it -- I used excel to build it, and if you want that file, let me know. The openscad file should be placed in the same directory with write.scad.The different stl files are renderings of different trends (1st ionization energy, Z effective, etc.) They are all labelled, but to use them as a "mystery trend" that needs explaining, you could always cover up the label with a piece of duct tape! The corners were warping a little (nothing too serious) on a previous version, and the table wasn't "centered" too well on its base -- it is a little better now. I printed on a replicator 2 with "natural" filament, and used a sharpie to color the symbols.(A shout-out to my 3rd, 5th, and 7th period chemistry students!)