TrendsTube ® (Free Download)
This chart is wrapped and joined like the Main Group of every Alexander Arrangement of Elements. By positioning the end of one period to be directly adjacent to the beginning of the next there is greater clarity to the inter-relationship of ionization energy of the elements before and after the Noble Gas elements being together, which, in a PT, are found at opposite ends of the flat periodic chart - overstretching the average student's inderstanding and teacher's credibility for the better student.
Interactivity: teacher download and print, student wrap, tape, and understand. Alexander 2017
CoValenTool ® (Free Download)
Another downloadable interactive device is this unique creation by Roy Alexander.
It is designed to show which families of the Main Group elements share electrons to form compounds - useful during the lesson, and as a later reference. It also calls attention to the inert nature of the Noble Gases.
After students cut and fold, and fold, and fold, etc., the position of elements that can share electrons may be moved to direct proximity. It illustrates that any elements of the adjacent group can form a simple two element compound, clarified by the relative positioning of valence shell electrons (a variant ot Lewis Dots) of all adjacent elements.
Using the old IUPAC Roman numeral column numbers lets the students to see immediately the number of electrons that are available in the valence shell of that column.
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last update 2/25/18