After a brief hiatus, chemists are continuing their forced march up the periodic table. The latest addition is seaborgium: element 106.
Nearly all the elements from hydrogen to uranium occur naturally on Earth. Beyond that, doing chemistry gets exceptionally difficult. To study an element heavier than uranium--which has 92 protons in its nucleus, and thus an atomic number of 92--you have to make it first, usually by slamming a light element into a heavy one at high speed and hoping some of the nuclei stick together. The first nine transuranic elements were produced in a flurry between 1940 and 1955--eight of them, beginning with plutonium, by a group that included American chemist Glenn Seaborg. (The group found elements 99 and 100 in the fallout from the first hydrogen bomb explosion, at Eniwetok Atoll in 1952; element 100 was in a garbage can.) But the pace has been slower ever since. ...
