Block (periodic table) in the extended periodic table whose outermost electrons are posited to include one or more g-orbital electrons. Block (periodic table) A block of the periodic table of elements is a set of adjacent groups. The term appears to have been first used by Charles Janet. The respective highest-energy electrons in each element in a block belong to the same atomic orbital type. Each block is named after its characteristic orbital; thus, the blocks are: The block names (s, p, d, f and g) are derived from the spectroscopic notation for the associated atomic orbitals: sharp, principal, diffuse and fundamental, and
History of the periodic table of periodic table, which he named "Vis tellurique" (the 'telluric helix'), after the element tellurium, which fell near the center of his diagram. With the elements arranged in a spiral on a cylinder by order of increasing atomic weight, de Chancourtois saw that elements with similar properties lined up vertically. His 1863 publication included a chart (which contained ions and compounds, in addition to elements), but his original paper in the "Comptes Rendus de l'Académie des Sciences" used geological rather than chemical terms and did not include a diagram. As a result, de Chancourtois' ideas received little attention until after