Chemical bonds

Chemical bond

The force of attraction which binds or hold two or more atoms of the same or different elements is called chemical bond.

Exp: It is formed by the attraction among atoms due to electrostatic force which arises from the charged particles that is proton and electron. It has two types.

1. Attractive forces: This force is present between opposite forces that is proton and electron. These forces result in the formation of bond.
2. Repulsive forces: This is force is present between same forces that is electron and electron or proton and proton.The bond between atom form when attractive forces become or overcome against the repulsive forces.

Types of chemical bond

There are four types of bonds

1. Ionic bond
2. Covalent bond
3. Coordinate Covalent or Dative bond
4. Metallic bond

Ionic bond

The bond which is formed by the complete transfer of one or more electrons between two or more atoms is called ionic bond.

Exp: In this type of bond the atoms is joined together by the transfer of electron. This involved the loss or gain of electrons which results in the formation of ions. These ions are hold together by the electrostatic forces.

Example: Sodium chloride of common salt is consisting of sodium which explosive in air and chloride which is very harmful but sodium chloride is very useful compound formed by the complete transfer of electrons. Sodium atom has only one atom in its outermost shell and wants to loss it and chloride has 7 electrons in its outermost shell and wants to gain it. Such as 

Na⁺¹    +    Cl^–1     ====è   NaCl     

Properties of ion bond

• Ionic bond is very strong that’s why it is normally solid.
• Ionic bond has high melting and boiling point.
• Ionic bond is soluble in polar solvent like water.
• Ionic bond conducts electricity both in molten and solution state.

Covalent Bond

The chemical bond which is formed by the mutual sharing of electrons between atoms is called covalent bond.

Exp: This bond is formed between the atoms which are not able to transfer the electron completely therefore these atoms share electron to become stable in nature and get stability. This bond is represented by single short straight line and this bond is formed between the elements of the group 13 to17.

Example: Hydrogen molecule is formed by the mutual sharing of electrons between two hydrogen atoms. In this way each atom get stability and become stable in nature.

HŸ+×H   or  HŸ×H   ====è   H₂

Types of covalent bond

There are three types of covalent bond

1. Single covalent bond
2. Double covalent bond
3. Triple covalent bond

Single covalent bond

A bond which is formed by the mutual sharing of one pair of electron is called single covalent bond. It is represented by a single short straight line.

Example: Chlorine molecule is formed by the mutual sharing of one pair of electrons between two chlorine atoms. In this way each atom get stability and have completed their outermost shell.

Double covalent bond

A bond which is formed by the mutual sharing of two pair of electron is called double covalent bond. It is represented by double short straight line.

Example: Oxygen molecule is formed by the mutual sharing of two pair of electrons between two oxygen atoms. In this way each atom get stability and have completed their outermost shell.

                                     

Triple covalent bond

A bond which is formed by the mutual sharing of three pair of electron is called triple covalent bond. It is represented by triple short straight line.

Example: Nitrogen molecule is formed by the mutual sharing of two pair of electrons between two Nitrogen atoms. In this way each atom get stability and have completed their outermost shell.

                                        

Coordinate  Covalent or Dative Covalent bond

A covalent bond in which shared pair or bond pair of electron is denoted by only one atom is called coordinate covalent or dative covalent bond.

Exp: In this type of bond the atom which accepts the elctron is called acceptor and the atoms which donates electrons is called donar. This bond is also donated by an arroe and the head of arroe is always toward the acceptor atom.

Examples:When nitrogen atom  id covalently bonded with three atom of hydrogen then its formed a molecule of ammonia NH₃ 

                                      

There is still a lone pair of electron on an ammonia. This lone pair can form another bond when NH₃ reacts with hydrogen ions in an acid then ammonium ion is formed.

NH₃ +   H^{+          ====>}         NH₄⁺¹

Metallic bond

The type of bond which is formed between the atoms due to mobile or free electrons is called metallic bond.

Explanation:This type of bond is formed only between metals where outermost shell of metals atom is not attracted strongly by the nucleus therefore atom can loss it very easily. As result these electrons of all metals atoms can move freely in space between atoms of a metal and act as a glue. It looks like the nuclei of metal atoms are immersed in a sea of electrons.

Properties of metal

• It is good conductor of electricity
• It has high melting and boiling point.
• It can be molded to any shape.

You May also Know

• Einstein's Big Theory
• Rutherford atomic Model
• Neils Bohr's Atomic theory