A pure element will always have an oxidation state of zero. The oxidation state is as high as +8 in certain elements, while it is as low as -4.

Reduction refers to a reaction where oxidation decreases. Oxidation and reduction are the two reactions that help in, formally transferring electrons. The term was developed by Antoine Lavoisier. The state can either be positive, zero, or negative. The state of oxidation of a specific element refers to the degree to which an atom can lose or gain its electrons. The oxidation state of elements in the periodic table The chemical reactivity on moving from top to bottom increases, and it decreases on moving across. The substance can react with itself or with some other substance and release energy. Hence their ability to conduct electricity is determined.Ĭhemical Reactivity – it refers to the energy or the force of a chemical substance to undergo a reaction. Metallic character – the metallic character of elements in a periodic table tends to increase on moving from top to bottom, and it tends to decrease on moving from the left towards the right. It increases on moving from left to right as more energy is released. The affinity of electrons – refers to the energy that is released when an electron is gained by an atom. On moving in a diagonal direction, atomic radius tends to increase. On moving from left to right, it increases, and on moving from top to bottom, it increases. Ionisation energy increases on moving horizontally across a period, whereas on moving in the downward direction, the ionisation energy decreases.Ītomic radii – the distance between the outermost electron and the nucleus is known as the atomic radius. Ionisation energy – this energy helps the atoms to remove the electrons. An exception in group 3 elements is present where electronegativity increases towards thallium. On moving in the downward direction, the electronegativity decreases. On moving from left to right horizontally in a periodic table, there is an increase in electronegativity. The Pauling scale is used to measure electronegativity. Some periodic trends and chemical reactivity in the periodic table are as follows –Įlectronegativity – measures the ability of a molecule to gain electrons within a chemical bond. The trends of the elements in a periodic table depend on various factors like electronegativity, ionisation energy, electron affinity, atomic radii, metallic character, and chemical reactivity. Periodic trends refer to the patterns of the properties of the chemical elements. The periodic trends and chemical reactivities of elements are shared below. The gas elements do not gain or lose their electrons because the electronic configuration is filled.

Hence the elements on the left side in the downwards direction are the highly reactive elements. In a period, the chemical reactivity decreases on moving towards the right, whereas in a group, chemical reactivity increases on moving downwards. Hence the electronegativity and the ionisation energy determine a chemical reaction. The higher the reactivity of the element, the easier it is to combine. The electrons between the elements are shared, or the elements lose or gain the electrons. These trends explain the periodicity observed in the elemental properties of atomic radius, ionization energy, electron affinity, and electronegativity.The rate at which a chemical substance or an element undergoes a chemical reaction is known as reactivity.

This happens because the number of filled principal energy levels (which shield the outermost electrons from attraction to the nucleus) increases downward within each group. Second, moving down a column in the periodic table, the outermost electrons become less tightly bound to the nucleus. As this happens, the electrons of the outermost shell experience increasingly strong nuclear attraction, so the electrons become closer to the nucleus and more tightly bound to it. First, electrons are added one at a time moving from left to right across a period. In addition to this activity, there are two other important trends. Stable octets are seen in the inert gases, or noble gases, of Group VIII of the periodic table. Elements tend to gain or lose valence electrons to achieve stable octet formation. These trends can be predicted merely by examing the periodic table and can be explained and understood by analyzing the electron configurations of the elements. The periodic table arranges the elements by periodic properties, which are recurring trends in physical and chemical characteristics.

Reactivity on periodic table