What is the difference between valency and valence electrons

Therefore, the valency of group VII elements equal to zero. Coming from Engineering cum Human Resource Development background, has over 10 years experience in content developmet and management. Your email address will not be published. Leave a Reply Cancel reply Your email address will not be published. Atomic excitation occurs when an electron gains enough energy to migrate jump to an outer shell.

Determination of Valence Electrons in an Atom Although the number of shells rises as we travel down a group, the number of valence electrons remains constant. While the number of valence electrons increases by one over time, the number of shells remains constant. What is Valency? The valency of an atom is equal to the number of valence electrons that this atom can gain or lose during chemical reactions. Or in other words: The amount of hydrogen atoms, chlorine atoms, or double the number of oxygen atoms that one atom of an element may combine with is referred to as its valency.

The valency of an element refers to the number of valence electrons in that element that participate in chemical processes. A chemical compound is created when two or more components are combined in a certain mass proportion. A stable compound is formed when one atom of one element unites with a specific number of atoms of another element.

All components have different capabilities for mixing. Valency of Metals A metal is an element with one, two, or three electrons in its valence shell except hydrogen and helium, which are non-metals. In chemical processes, metals tend to shed their valence electrons and complete their octet. They have 1 electron in their outermost shell. So, the valency of Sodium is 1 as shown below:. They have 2 electrons in their outermost shell. They have 3 electrons in their outermost shell.

To complete its octet, a non-metal requires 3 or 2 or 1 or 0 electrons. They have 5 electrons in their outermost shell. They have 7 electrons in their outermost shell. For example, atoms of Li, Na, K lose one electron so their electrovalency is 1, atoms of Mg, Ca, Ba lose two electrons , so their electrovalency is 2.

The atoms of O, S gain two electrons so their electrovalency is 2 and the atoms of Cl, Br, I gain one electron so their electrovalency is 1. So they do not lose, gain or share electrons. So their valency is zero. For example, oxygen atom shares two electrons with two H atoms to form H2O. In chemical terms, the valency of an element is the number of bonds it could form. The valence electrons would be the electrons that are available to take part in this bonding.

Therefore, the main difference between valency and valence electrons is that valency is the number of bonds that can be formed by an atom or an element whereas valence electrons are the electrons that take part in this bond formations. It is important to note the fact that univalent atoms are considered here, as they would pair up with one electron at a time.

However, if an element like Oxygen, which is a divalent atom, is used for this purpose, the valency will be equal to double the amount of Oxygen that took part in the formation of bonds. A valence diagram of a compound would show the connectivity of atoms in lines, and this would not necessarily represent a pair of shared electrons.