Chemistry Unit 4- Periodic Table and Periodic Trends

The atomic radius is the physical size of the atom and the ionization energy is the energy required to completely separate the electrons from the atom. In the periodic table, the cyclic trend of atomic radius and ionization energy is an acceptable range. However, in some cases, certain elements may not follow predetermined regular trends. These are areas where trends are abnormal. In this figure, these four exceptions are circled, but only three exceptions # 2, # 3, and # 4 are explained. The purpose of this report is to explain the unpredictability of these designated areas and provide a concise inference about the cause of the anomalies from the viewpoint of electronic configuration.

Acceptable periodic trends of atomic radii are as follows. The atomic radius increases from one group of the periodic table down to the left from the bottom. Focus will tend to be "from right to left" because there are elements that are abnormally involved and end the current desktop. As the effective nuclear charge Zeff increases from left to right, the atomic radius decreases from left to right. Zeff is the overall attraction of electrons from the nucleus, the greater the attraction between the nucleus and the electron, the larger the Zeff. This means that as the number of protons in the core increases, Zeff also increases because the attractive force between the core and individual electrons increases. The larger the electrons extend towards the nucleus, the smaller the atomic radius. However, this trend is not necessarily being followed. With regard to the trend of atomic radii on the periodic table, the following exceptions occur: