Reflections on the Nature of the Periodic Table of the Elements: Implications in Chemical Education

The periodic table of the elements (PTE) results essential to understand our nature and place in the whole of beings. The same happens with our food, drugs, materials, etc. A series of questions were asked to introduce PTE and provide answers. The ideas in PTE should be valued by the number of questions that they generate. The PTE was related to electron configurations. The emergence of elements (nucleosynthesis) in physics was explained. The PTE results essential to understand our nature and place in the whole of beings. The same happens with our food, drugs, materials, etc. Schwarz and Rich asked a series of questions (Qs) to introduce PTE and provided answers. The ideas on PTE should be valued by the number of questions that they generate. Q1. Why are the halogens and alkali metals among the first groups treated in chemistry courses? Q2. What is the physical origin of the periods' lengths? Q3. Why are the closed p6 shells of the inert gases more stable than other closed shells, viz. s2 and d10 of chemically active metals (of groups 2, 12 and 10)? Q4. Textbooks give the electron configuration of the transition elements as ns2(n – 1)dG–2 with a few exceptions (G is the number of valence electrons or group number in PTE and n, the main quantum number or period number). Why is transition-metal chemistry practically pure d-atomic orbital (AO) chemistry? Etcetera. A need exists to develop theoretical and experimental research on PTE to understand periodic properties and the periodic law.