Please explain me the covalent bonding, lewis dot structure and ionic bonding step by step with example..

Asked by Prachi Panwar | 2nd Jun, 2013, 03:09: PM

Expert Answer:

The Lewis structure model generally follows the octet rule and provides a framework to understand covalent bonding. Lewis structures represent valence electrons as dots and bonding electrons as lines. Lewis structures do not represent inner electrons; only valence electrons are shown.

Here is a step-by-step procedure for writing valid Lewis structures for any given molecular formula:

  1. Count the total number of valence electrons by summing the group numbers of all the atoms. If there is a net positive charge, subtract that number from the total electron count. If there is a net negative charge, add that number to the total electron count.
  2. Draw single bonds to form the desired connectivity.
  3. Add lone pairs and multiple bonds, keeping the octet rule in mind.
  4. Add formal charges as needed.

Level 1 (basic)

1. Add up all the valance electrons of the atoms involved.  ex CF4   

     So C has 4 and F has 7 (x4  we have 4Fs) = 32 valence electrons

2. You need to pick the central atom. This is usually easy, this atom will be surrounded by the others. Never H.

 So C will be surrounded by F's.

3. Now we create our skeleton structure by placing bonds in. A bond is a dash that represents 2 electrons.

Ionic bonds hold atoms together through electrostatic forces. Covalent bonds operate through an entirely different means: the sharing of electrons. By sharing electrons, two atoms can mutually complete their valence shells to become more stable. A molecule is a collection of atoms held together by covalent bonds. For example, below, two hydrogen atoms, each with a single electron, can share their electrons to form a covalent bond and create the diatomic hydrogen molecule. In this molecular state, both individual hydrogen atoms attain the noble gas configuration of Helium. 

Answered by  | 4th Jun, 2013, 10:49: AM

Queries asked on Sunday & after 7pm from Monday to Saturday will be answered after 12pm the next working day.