The Periodic Table

The Periodic Table is the arrangement of elements in tabular form based on atomic numbers and electronic configurations. The elements are presented in order of increasing atomic number (number of protons in the nucleus) in a table with 9 rows and 18 columns (which are also called groups). Although there are 18 groups in total, there are only 8 main groups based on the number of valence electrons. So if two elements had the same number of main electron shells, then they would be placed in the same row in the periodic table. If two elements had the same number of valence electrons, then they would be placed in the same group. If an element had an atomic number which was higher than an element in the same row, it would be placed to the right of it in the periodic table as it is organized in ascending order. For example, the elements carbon and nitrogen both have 2 main electron shells – this is why they are both placed in the second row of the periodic table. Phosphorus on the other hand has 3 main electron shells, but has five valence electrons just like nitrogen – this is why it is placed just underneath nitrogen. Thus, understanding the rules and complexities of the periodic table may be useful for chemists in predicting elemental properties as well as similarities and differences between the elements. © BrainMass Inc. brainmass.com April 27, 2024, 2:06 am ad1c9bdddf