Electronic Configuration
The most stable energy state of electron is its ground state. The filling of electrons in various sub shells in its ground state is determined by following various rules. These are used to write Electronic Configuration of Elements.
The first rule is Aufbu rule which states that the filling of electrons are started from the lowest energy level and it is filled in ascending order of energies of various energy levels. Like 1s, 2s, 2p, 3s, 3p, 4s, 3d, 4p, 5s, 4d …and so on. The next rule is Pauli’s exclusion rule which states that it is not possible to fill more then two electrons in any orbitals and both the electrons must have opposite value of spin.And the last rule is Hund’s rule.
This rule is given for pairing of electrons on any orbitals sub shell. So it states that the pairing of electrons in sub shell is not possible until all the orbitals are singly filled. And all these singly filled orbitals must have parallel spin electrons.Please express your views of this topic Definition of Chemical Formula by commenting on blog.
Thus all these rule help us to write the electronic configuration of ground state of elements. So for writing Electronic Configuration of the Elements, first the orbital symbol is written and then the principal quantum comes before the symbol. Then the number of electrons is written as superscript of orbital symbol on the right hand side.
For example if we write for hydrogen, as we know it has only one electron which comes in the 1s orbital. So the configuration is 1s1. If we write the configuration for carbon element which has atomic number 6, filling of electrons is started from 1s orbital.
After filling 1s and 2s orbitals with 2-2 electrons, we fill in 2p sub shell. As we know that 2p sub shell has total three sub shell and now total two electrons are remained. Is this topic Organic Chemistry Chirality hard for you? Watch out for my coming posts.
Now apply Hund’s rule, so pairing of electrons cannot be possible in orbitals of any sub shell until all the orbitals get one electrons. Thus the configuration of carbon is written as 1s2, 2s2, 2px12py1.
The Valence Electron Configuration is the outer most electronic configuration of any element. Like the electron configuration of chromium Cr is [Ar] 4s1, 3d5. If we write the complete configuration of Cr then it is 1s2, 2s2, 2p6, 3s2, 3p6, 4s1, 3d5.
So the last electrons of Cr are filled in 4s and 3d sub shell which is its valence shell configuration. We can write other elements configuration also in this form. The various configurations of some elements are shown in Electron Configuration Table that is shown below.
The first rule is Aufbu rule which states that the filling of electrons are started from the lowest energy level and it is filled in ascending order of energies of various energy levels. Like 1s, 2s, 2p, 3s, 3p, 4s, 3d, 4p, 5s, 4d …and so on. The next rule is Pauli’s exclusion rule which states that it is not possible to fill more then two electrons in any orbitals and both the electrons must have opposite value of spin.And the last rule is Hund’s rule.
This rule is given for pairing of electrons on any orbitals sub shell. So it states that the pairing of electrons in sub shell is not possible until all the orbitals are singly filled. And all these singly filled orbitals must have parallel spin electrons.Please express your views of this topic Definition of Chemical Formula by commenting on blog.
Thus all these rule help us to write the electronic configuration of ground state of elements. So for writing Electronic Configuration of the Elements, first the orbital symbol is written and then the principal quantum comes before the symbol. Then the number of electrons is written as superscript of orbital symbol on the right hand side.
For example if we write for hydrogen, as we know it has only one electron which comes in the 1s orbital. So the configuration is 1s1. If we write the configuration for carbon element which has atomic number 6, filling of electrons is started from 1s orbital.
After filling 1s and 2s orbitals with 2-2 electrons, we fill in 2p sub shell. As we know that 2p sub shell has total three sub shell and now total two electrons are remained. Is this topic Organic Chemistry Chirality hard for you? Watch out for my coming posts.
Now apply Hund’s rule, so pairing of electrons cannot be possible in orbitals of any sub shell until all the orbitals get one electrons. Thus the configuration of carbon is written as 1s2, 2s2, 2px12py1.
The Valence Electron Configuration is the outer most electronic configuration of any element. Like the electron configuration of chromium Cr is [Ar] 4s1, 3d5. If we write the complete configuration of Cr then it is 1s2, 2s2, 2p6, 3s2, 3p6, 4s1, 3d5.
So the last electrons of Cr are filled in 4s and 3d sub shell which is its valence shell configuration. We can write other elements configuration also in this form. The various configurations of some elements are shown in Electron Configuration Table that is shown below.