Periodic Trends

In the periodic table SparkNote, we discussed many simple periodic trends. In this section, we describe more complex trends, where understanding depends on knowledge of atomic structure.

Before understanding these trends, we need to make a brief review and establish some terminology. As we saw in the previous octet rule section, atoms tend to lose or acquire electrons, and the stability of the complete valence shell and complete valence shell is obtained. Since the electrons are negatively charged, atoms lose or acquire electrons, and the atoms are charged positively or negatively. A group of atoms or atoms with a net charge whether positive or negative charges are called ions. A positively charged ion is a cation, while a negatively charged ion is an anion

This time we will discuss periodic trends of atomic size, ionization energy, electron affinity and electronic inductance.

The atomic size of an atom, also called the atomic radius, represents the distance between the nucleus and its valence electron. Keep in mind that the closer the electrons are to the nucleus, the lower the energy and the closer the energy is.

Moving from left to right over a period, the atomic radius decreases. The nucleus acquires protons moving from left to right, increases the nuclear positive charge and increases the attraction of the electrons to the nucleus. Indeed, as the elements move from left to right over a period of time, electrons are also added, but these electrons are in the same energy shell and do not provide enhanced shielding.

The atomic radius increases and moves downward. The proton descends again, but the new energy shell of the electron also descends. The new energy shell provides shielding and enables valence electrons to experience only minimal proton positive charge.

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.

The general trend of ionization energy is to increase by group and to increase from left to right. Since elements that are abnormally involved appear continuously in the periodic table, a tendency of "from left to right" can be seen. The reason for this tendency depends on Zeff. As the number of protons in the nucleus increases, Zeff increases. The more protons in the nucleus, the greater the attraction between a single electron and the nucleus. In other words, the higher the Zeff.Zeff, the closer the electron is to the nucleus and the more energy it needs. Please separate these electrons from atoms. However, in some cases, this trend does not apply to specific elements. Regarding the tendency of the ionization energy of the periodic table, the following abnormality occurs.

The period is the horizontal line of the periodic table. Groups generally have a more pronounced periodic tendency, but the elements of the lanthanides and acts form two elementary levels of the element series, like the f-block, the horizontal trend is a vertical group Trend is more important. Elements with the same period show the trend of atomic radius, ionization energy, electron affinity and electronegativity. Moving from left to right over a period of time, the atomic radius usually decreases. This occurs because there are additional protons and electrons in each successive element. This attracts electrons close to the core. This decrease in atomic radius also increases as the ionization energy moves from left to right over a period of time. The more closely the elements are combined, the more energy is needed to remove the electrons. Electronegativity increases in the same way as ionization due to the pulling force applied to electrons