2003/08/01 by William B. Jensen · 12 citations
Chemistry · Computer Science · #Chemical Thermodynamics and Molecular Structure #Geochemistry and Geologic Mapping #History and advancements in chemistry
paper · doi:10.1021/ed080p952
openalex publication_date 2003/08/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/30
Following an earlier article on the positions of lanthanium and lutetium in the periodic table ( J. Chem. Educ. 1982, 59, 634-636), the author notes that introductory textbooks, inorganic textbooks, and advanced monographs on coordination and organometallic chemistry are increasingly treating zinc, cadmium, and mercury as transition or d-block elements, rather than as main-block elements. The author reviews the historical evolution of the concepts of transition elements and d-block elements, evaluates the chemical and spectrosopic evidence for each placement, and concludes that these elements are unambiguously main-block elements and that there is a fundamental bifurcation of group 2 at magnesium into a Ca–Ra branch and a Zn–Hg branch. The author also reviews various ways of representing this bifurcation using spatial position in the periodic table and various labeling schemes.