The Periodic Table

The periodic table of the elements is an immensely important tool for presenting information on the known elements in such a way that predictions about their properties can be made. Physical Science students should not take the time nor trouble to memorize the periodic table - the important skills are to be able to read the table and understand the patterns and trends it presents. Today's activity allowed students to draw Bohr models of atoms based on the number of protons and neutrons specified. Electrons had to be presented in their proper configuration in the electron cloud and the atomic mass calculated from the nuclear particles. Monday, we'll complete our discussion of the basic organization of the periodic table and how the concepts of ions and isotopes fit into the picture. We may not have time to cover the third section of this chapter (which is presented in the lecture packet), but that's fine. The meat of the chapter is in the first two sections, anyway.

The periodic table is like anything in science - it changes with new information. We've added new elements and the original organization by Mendeleev was based on atomic mass, not atomic number (Henry Mosely did the reorganization for that piece). However, with more and more information about elements being found, such as orbitals and quantum numbers, other variations of the basic periodic table can be found. I'm not talking about those "Periodic Table of the Vegetables" posters you see around, but rather a real reorganization of the elements that includes or is based around a different property than simply the atomic number. These alternative versions are not widely used, but they are definitely cool to look at. Here are a few examples:

This is the table designed by Professor Theodor Benfey in 1960



This one is by Mohammed Abubakr



The Najderek table emphasizes the energy levels and orbitals nicely:



The Physicists table adds in quantum numbers:



This one is just sorta weird - but pretty!