Details of Answers about All Periodic Tables
Why do we need 3-D models when flat charts are so handy to use?
Most 3-D models are intended to show an unbroken numerical sequence of the elements for new students, allowing the learner to stay on track while tracing trends, similarities, or differences for any element, clarifying the relationships of the elements for high school through college level chemistry and affiliated fields, and often provide many improvements over the flat periodic table for serious chemists and students as well.
As in the study of geography, where the globe introduces the concept, then maps are employed to permit closer examination of places on the globe -- however distorted they may become by comparison -- the 3-D chart avoids the distortions necessary to portray element relationships on a flat surface, easing the learner into the daunting informational device that is the periodic table. They also provide more motivational, interesting, and usually hands-on, educational possibilities, while also appealing to a wider range of intellectual types.
Details of answer;
Most 3-D models are intended to repair the grid's broken numerical sequence of the elements for new students, allowing the learner to stay on track while tracing trends, similarities, or differences for any element, clarifying the relationships of the elements for high school through college level chemistry and affiliated fields. Often they provide other improvements over the flat periodic table for serious chemists and students, but the occupation of the orbitals by electrons should always be clearly recognizable.
During Glenn Seaborg’s work on nuclear energy in the Manhattan Project during WWII he placed the new radioactive elements, and other actinoids, in a new location, below the lanthanoids, the rare earth f-block. Before he died, he had an Alexander Arrangement, and had stated that this 3-D method was now the correct way to show the Rare earths - integrated into the main body.
A 3-D model, such as the Alexander Arrangement of Elements, harks back to De Chancourtois’ first (helix/spiral) periodic arrangement (Alexandre to Alexander?) and adheres to the “arranged in order” aspect of Mendeleev’s Law, unlike a grid table with its multiple sequential breaks, and is gracefully formed as well, resolving the argument between the relative merits of utility and beauty in chemistry.
This type of model, more accurate in general, but with little detail, is mostly useful in introducing the new student to an accurate representation of the relationships and independence of the elements and their groupings, and less than useful as a reference when actually doing chemistry. 3-D models create an excellent foundation for later necessary use of the other flat charts – static and interactive – but suffer from not being available in as many versions as the flat chart, or to be interactive except during assembly.
Some 2-D element periodic tables (usually spiral), and some in 3-D, have been developed as an improvement for learning for new students. The Alexander Arrangement of Elements, for instance, that Glenn Seaborg referred to as a “futuristic” periodic table, provides a less off-putting, hands-on, visually attractive, unique creation for the young student to own, rather than for reference alone like flat tables. It is intended to avoid initial introduction of the confusion and inconsistencies in the flat table by arranging the elements contiguously and continuously according to atomic numbers without disturbing the accepted group and property interrelationships of elements.
World of elements, elements of the World; Quadbeck-Seeger, the Periodic Table; Scerri, AllPeriodicTables.com