unobtainium

Though seemingly a human construct and just an arbitrary but satisfying stopping point, the once toothiness of the Periodic Table of Elements that is no more is a significant subject and the arrangement and ordering of the possible chemical components hang on the non-negotiable properties of physics and nature.
The columns correspond to the valances (shells) of electrons that can “orbit” a given atom of a given heft and proximity is predictive of characteristics and foretold of all the gaps decades prior to their discovery. Even though there was no surprises found in the missing cells, it’s pretty keen to have all that apparently ironed out. Chemistry is not some tin-pot dictator whose managed to complete one more row of medals and ribbons of some uniform that he is wont to prance about in but rather this—guardedly, could represent all normal matter in the Universe, with no new additions to follow. Structurally, we cannot expect to find anything bigger as the mobil would not have a state of equilibrium, although most of the heavier elements with more than one hundred protons exist only in the laboratory as a smattering of atoms that quickly decay.  Normal, experiential matter however does just comprise some fifteen percent of what’s out there with the overwhelming surplus of the Cosmos made of hypothetical Dark Matter, which only shows itself in its gravitation wake and could be made out of a completely different set of elements.