I have here a model representing this figure projecteg in space; in it the elements are supposed to folloW'”6ne another at equal distances along the figure of “eight spiral, a gap of one ...

Naturally, they have short lifetimes and break into smaller elements spontaneously. Typically, these elements have atomic numbers greater than 104 and are not found in abundant quantities in nature.

ABOUT ARGON, THE INERT; The New Element Supposedly Found in the Atmosphere. DIFFERENCES IN WEIGHTS OF GASES Experiments of Lord Rayleigh and Prof. Ramsay -- Henry Cavendish and Phlogiston ...

Argon didn't fit in the periodic table known at the time, and it was Ramsay who suggested including an additional column, group 18. Helium, and other elements subsequently discovered, were to find ...