Historical, spectroscopic and chemical comparison of noble gases.- The chemistry of the noble gas elements helium, neon, and argon — Experimental facts and theoretical predictions.- Chemistry of inorganic vapors.- Heavy elements synthesized in supernovae and detected in peculiar A-type stars.- Crookes and marignac — A centennial of an intuitive and pragmatic appraisal of “chemical elements” and the present astrophysical status of nucleosynthesis and “dark matter”.