Valence electron periodic table list
(Source: examfear) Examples of Valency on the basis of Chemical Formula Ammonia (NH 3) Therefore, valence electron in chlorine is 7 and it needs to gain 1 electron from the outermost orbit to attain octet. 2, 8, 7 electrons are distributed in the shells K, L, M respectively. The electronic configuration of chlorine can be written as 2, 8, 7. The atomic number of chlorine is 17 (Z=17). Therefore, valence electron in sodium is 1 and it needs to lose 1 electron from the outermost orbit to attain octet. 2, 8, 1 electrons are distributed in the shells K, L, M respectively. The electronic configuration of sodium can be written as 2, 8, 1. The atomic number of sodium is 11 (Z=11). You can download Structure of Atom Cheat Sheet by clicking on the download button below Thus, it will gain one electron to obtain octet so the valency of fluorine is 1. It is difficult to lose 7 electrons but it is easy to gain one electron. For instance, Fluorine has 7 electrons in its outermost orbit. Stability is also determined by the ability of atoms to gain electrons. Therefore, the valency of magnesium is 2. Similarly, magnesium has 2 electrons in its outermost orbit and it needs to lose them to attain octet and obtain stability. This capacity of an atom will also determine the valency of an atom.įor instance, hydrogen has 1 electron in its outermost orbit so it needs to lose 1 electron to attain stability or octet. Therefore, a capacity of an atom is the total number of electrons gained, lost, or shared to complete its octet arrangement in the outermost atom. An atom has to gain, lose or share a particular number of electrons from its outermost orbit to obtain complete octet. If the outermost shell of an atom has a total of 8 electrons then the atom is said to have attained a complete octet. Valence Electron Achieving Complete Octet It will also help to determine the valency of an atom. However, the reactivity of other elements depends upon their capacity to gain noble gas configuration. This is why noble gases are least reactive because their outermost orbit is completely filled. Understand the concept of Sub-atomic Particles here in detail. Their combining capacity becomes negligible or zero. However, if the outermost orbit is completely filled then very little to no chemical activity is observed in the particular element. The valence electrons take part in any chemical reaction because the outermost orbit usually contains more energy than the electrons present in other orbits.Īccording to the Bohr-bury scheme, the outermost orbit of an atom will have a maximum of 8 electrons. The electrons present in the outermost shell/orbit of an atom are called valence electrons. Towards Quantum Mechanical Model of AtomĮlectrons in an atom are arranged in different orbitals (shells) represented as K, L, M, N, and so on.Development Leading to Bohr’s Model of Atom.How are Electrons Distributed in Different Orbits (Shells)?.Browse more Topics under Structure Of Atom Therefore, it is the capacity of an atom of a single element to react and combine with particular numbers of atoms of another element. Valency is the measure of the combining capacity of atoms or molecules.