periodic table valence electron definition

The characteristics of the elements in these families are determined primarily by the number of electrons in the outer energy shell.

Elements are classified into families because the three main categories of elements (metals, nonmetals, and semimetals) are very broad. (CC BY-SA 2.Element families are indicated by numbers located at the top of the periodic table.Īn element family is a set of elements sharing common properties. Image Courtesy: “Electron shell 010 Neon – no label” by commons:User:Pumbaa (original work by commons:User:Greg Robson) – (corresponding labeled version). Therefore, the valency of group VII elements equal to zero. Noble gases do not accept or remove electrons to achieve the octet rule since they have already completed the last shell. Valency Electrons: Valency is a measure of the ability to form bonds with other elements or molecules. Their outer shell is complete, and it contains eight electrons in the outermost shell (except Helium –He) so that group VIII electrons have eight valence electrons. Valence Electrons: Group VIII elements are the noble gases, and they are chemically stable. Therefore, the valency of non-metal elements is calculated by subtracting the total valence electrons from 8.įor Chlorine, Number of valency electrons = 8-7 =1Ĭharacteristics of Valency and Valence Electrons Valency and Valence Electrons of group VIII elements In general, for metal elements (elements in group I, II and III), the number of valence electrons is equal to the number of valency electrons they remove the electrons in the valence shell to achieve the octet structure.īut, non-metal elements accept electrons to achieve the electron configuration of the nearest noble gas. Valency Electrons: The number of electrons that should be accepted or removed to attain the electron configuration of the nearest noble gas is called “valency electrons” or the “valence” of an atom. For “s” and “p” group elements, the number of valence electrons is equal to their group number. Valence Electrons: The electrons in the outermost shell of an atom are called “valence electrons”. What is the difference between Valency and Valence Electrons? Definition of Valency and Valence Electrons Number of Valency Electrons = (8- Number of Valence Electrons) Number of Valency Electrons = Number of Valence Electrons The number of valence electrons in an element determines the group in the periodic table. When elements form cations, they remove electrons from the valence shell. Most of the time, these are the electrons, which take part in chemical bonding. Because of this reason, the outermost shell of an atom is called “valence shell”.

The number of electrons in the outermost shell of an atom is called “valence electrons”. In some atoms, the number of valence electrons is equal to the number of valency electrons. It is the electrons in the outermost shell that usually contribute to form chemical bonds. Valency electrons and valence electrons are inter-related terms, and the key difference between valency and valence electrons is best explained in their definitions valence electrons are the electrons in the outermost shell of an element whereas valency electrons are the number of electrons that should be accepted or removed to attain the nearest noble gas configuration.

Key Differences – Valency vs Valence Electrons

Periodic table valence electron definition