Let's construct  a pyramid from square details (moduls, building-blocks) Let's improve the three-dimensional model of the periodic system. We’ll take advantage of the opportunity to change the size, colour and form of component elements. The four-coal pyramid isomorphic to the one considered above is given below with the following changes:  The balls are replaced with square briquettes (building-blocks); each briquette denoting an individual (separate) element;  The colour of these elements is changed;  The next square module is added to the basis of the pyramid. This module has the side of 5 conventional units and height of 4 conventional units (in the figure two of its edges have violet (lilac) colour). Figure 13. Pyramidal system of chemical elements. Updating 1. The extended variant for 168 elements. Each element is designated by an individual (separate) briquette (building-block). The number of elements inside any period with the same named external electron shells (theyare painted in the traditional tables with individual colours) represents a series of the double consecutive odd numbers (2, 6, 10, 14...). This fact permits us traditionally to paint the briquettes having represented gnomons as it is shown in the figure. Quantum Mechanics Every electron in an atom has a unique (different) set of quantum numbers. These quantum numbers taken as a set help to physically describe the three dimensional probability region that we call the atomic orbital. The first quantum number in a set is called the Principle Quantum Number and is symbolized by the letter "N". Sometimes this number is referred to as the "shell". N can have a value of any positive integer beginning with the value of 1. There is a rule that defines the maximum number of electrons that can have a value of N as part of the physical description of the atomic orbital. This is called the 2N squared rule. The maximum number of electrons that can be assigned an N value specified is 2N2. For example for an N value of 1 you could have a maximum of 2(1)2 or 2 electrons whose probability regions are partially described by an N value of 1. The maximum number of electrons in an atom whose orbitals could be partially described by an N value of 2 would be 2(2)2 or 8. (URL: http://edie.cprost.sfu.ca/~rhlogan/quantum.html) The model, offered to your attention, visualizes this 2N squared rule.