Lewis Theory | Chemic Bonding Of Lewis Theory |

Lewis Theory | Chemical bonding of Lewis Theory |.

In 1916 W. Kossel together with G.N. Lewis set forrad the electronic theory of chemic bonding. It was suggested that inwards a chemic reaction, the atom of an chemical ingredient adjusts their electronic configuration to that of the nearest noble gas. The atoms larn 2 electrons, duplet configuration or 8 electron octet structure. For example, H, Li, together with Be acquire ns² and all other atoms tend to attain ns² np⁶ configuration. On the footing of this octet theory, the chemic bonds stimulate got been divided into the next iii types:

1. Ionic or Electrovalent Bond.
2. Covalent Bond.
3. Co-ordinate bond.

Ionic Bond.

The bond formed yesteryear the consummate transference of ane or to a greater extent than electrons from ane atom to or together with thus other atom is called the ionic or electrovalent bond. This is formed betwixt the elements of depression ionization potential values (i.e., elements of grouping I-A together with II-A) together with the elements amongst a high electron affinity values such every bit the chemical ingredient of Group Vi together with Vii-A.

Examples.

NaCl:

• Sodium loses ane electron to achieve the electronic configuration of neon,1s², 2s², 2p⁶.
  
• Chlorine gains ane electron to larn the electronic configuration of argon ( 1s² 2s² 2p⁶ 3s² 2p⁶)
  
• The oppositely charged ions formed inwards this agency are held together yesteryear the electrostatic forcefulness of attraction.
  

CaCl2:

• Calcium loses two-electron to form Ca²⁺ ions together with acquires electronic configuration of argon ( 1s² 2s² 2p⁶ 3s² 3p⁶)
  
• These 2 electrons are taken upwards yesteryear 2 chlorine atoms to form  ‎Cl⁻ ‎ions.
  
• Due to the electrostatic forcefulness of attraction, these ions pack themselves inwards a crystal lattice.
  

Covalent Bond.

"A bond formed yesteryear the usual sharing of electrons betwixt 2 atoms is called Covalent Bond". The atoms amongst aught or depression electronegativity differences commonly shape covalent bonds.

Examples:

Formation of H2:

• Two hydrogen atoms portion their electrons together with achieve locomote a configuration of helium, (1s²)
  

H2O Molecule:

• Two hydrogen atoms achieve the configuration of Helium (1s²) together with oxygen acquires Neon configuration (1s² 2s² 2p⁶), inwards the formation of H2O.
  
• Similarly, inwards the formation of NH3. each atom tends to larn element of group 0 configuration
  

Co-ordinate covalent Bond.

"A covalent bond inwards which both inwards electrons are donated yesteryear ane of the atoms is called Co-ordinate covalent bond. The atom which donates the electron couplet is called the donor atom together with the atom which accepts than for bond formation is called the acceptor. This bond is represented yesteryear an arrow that runs from donor to acceptor atom.

Examples:

Formation of NH+4 : 

• Lone couplet electron of nitrogen is donated to H⁺ to shape Co-ordinate covalent bond.
  

Formation of H3O+:

• Lone couplet of electron on oxygen forms a co-ordinate covalent bond with H⁺.