5. CHEMICAL BONDING
One or more Atoms combine together to
form the Molecule. The attractive force
between these atoms are called chemical
bonding.
eg : P4 ,O2 , Nacl, etc
6. The Chemical bonding is mainly
two types .They are,
1. Ionic bonding.
2. Covalent bonding.
7. IONIC BONDING
Ionic bonding is formed by the
exchange of electrones between the
electro positive and electro negative
atom.
OR
Ionic bond is formed by the
attraction between the ions.
Eg: Na + F NaF
8. Example 1.
Atomic symbol Atomic number(z) Configuration
Na ( sodium) 11 2,8,1
F ( Flurine) 9 2,7
Na + F Na + F NaF
9. Example 2.
Atomic symbol Atomic
number(z)
Configuration
Na( Sodium) 11 2,8,1
Cl(Chlorine) 17 2,8,7
Na + Cl Na + Cl NaCl
10. COVALENT BONDING
Covalent bonding is formed by the
shairing of electrones between two
atoms. It is denoted by using the
symbol ‘ ` .
Eg. Cl + Cl Cl2
11. Example 1.
Atomic symbol Atomic number(z) Configuration
Cl(Chlorine) 17 2,8,7
Outer most shell of Cl is given as below
Cl Cl
Cl + Cl Cl Cl Cl Cl (Cl2)
Here pairing is one pair of electrones (2 electrones)
12. Oxygen outer most shell has 6 electrones
O + O O O O2
Here 4 electrones shaired(2 pair)
14. Properties of Ionic & Covalent bond
Properties Ionic Compound Covalent Compound
State Solid Solid,Liquid.Gas
Solubility Dissolve Does not Dissolve
Electric
conductivity
Conduct In
solution or molten
state
Do not conduct
Melting point High Too low or Too
high
Boiling point High Too low or Too
high
15. Electron Theory of Valency
The Octect electron configuration
reduce the energy and gives more
stability to Atoms ,other atoms enter
into Chemical bonding in order to
attain stability by acquiring octect
electron configuration in the outer
most shell. This is the Electron theory
of Valency.
