Introduction to covalent bond:
Covalent bond is structured by dividing of one or more electrons between atoms. Example covalent bond is present between the hydrogen and oxygen in water molecule. Based on the number of distributed pair electrons the covalent bond is classified as follows
- Single covalent bond
- Double covalent bond
- Triple covalent bon
Single Covalent Bond:
Single covalent bond:
One of the important conditions in electronic configuration is valance band hold eight electrons in the outer most shell. When both the joining atom, which share one electron from the constant electronic configuration of the close to the inert gas, give one electron each to pair of electron which is equally splited by both the atoms.
We will discuss about the single covalent bond. A single covalent bond shaped when two atoms equally share a couple of electron. By doing so, the atoms attain stable octet electronic pattern. In single covalent bonding, overlie of the atomic orbitals having an electron from every of two atoms of the bond obtain place ensuing in equal distribution of the pair of electrons.
The interatomic single bond therefore shaped owing to the partly cover of tiny orbitals of electrons is known as a covalent bond. Normally the orbitals of the electrons in the valency shell of the atoms are used for electron sharing. The shared pair of electrons lies in the middle of the covalent bond. Including the shared pair of electrons the atoms of the covalent bond attain the stable octet configuration.Therefore in hydrogen fragment a covalent bond consequences by the partly cover of the two s orbitals every hold an electron from each of the two H atoms of the molecule. Each H atom attains ‘1 S2’ filled K shell.
It should be produced by distribution of s, p, d, f electrons also.The outer single shell electronic configuration of atom is 3s2 2px2 2py2 2pz1. When each chlorine atom mutually share the 2pz unpaired electron contributed from each Cl atom of the molecule, a covalent bond is produced. By doing so, each chlorine atom attains argon electron pattern.
In the phosphine PH3 molecule, three hydrogen atoms combine with one phosphorous. Three covalent bonds are grouped in PH3. They are twisted by shared distribution of a couple of electrons surrounded by the two atoms of a bond. Every carbon atom absolute its steady octet and every H atom have finished K shell.
These small single orbitals are said to be definite raw-boned relationships flanked by every other, and therefore the valence bond replica be able to productively forecast the tie angles pragmatic in simple molecules.
Example for Single Covalent Bond:
When two atoms share one pair of electrons within the outer most shell is called as single covalent bond.
Consider two atoms named as ‘C’ shares each one electron in the outer most shells. Then get eight electrons in the outer most shells. This type of bond is called as single covalent bond.
Examples for single covalent bond:
Formation of chlorine molecule:
The representation of chlorine is Cl2.
Atomic number =17
Electronic configuration =2, 8, 7.
Chlorine contains 7 electrons in the outer most shell. The outer most shell must contain eight electrons but one electron is missing in the chlorine valance shell. When chlorine contains eight electrons in the outer most shell that get constant electronic configuration. Combination of two chlorine atom produces a chlorine molecule. Every chlorine atom requires one electron for constant electronic configuration. So every chlorine atom shares one electron with other atom. Now the chlorine get eight electrons (2, 8, and 8) in the valance shell (constant electronic configuration).
Diagram representation of chlorine molecule from chlorine atom:
Formation of hydrogen chloride molecule:
Hydrogen has one electron in the outer most shell. The chlorine contains seven electrons in the outer most shell. When the hydrogen and chlorine atom combined produce a hydrogen chloride molecule. Hydrogen chloride molecule gets the constant electronic configuration in the valance shell. Each atom shares only one electron in the outer most shell. This type of bonding is called as single covalent bond.
Diagrammatic representation of formation of hydrogen chloride molecule: