Electron dot structure Class 10

As a class 10 student, you must know about the electron dot structures of different molecules. The electron dot structure is also useful for the students of classes 11 and 12. In this topic, we will discuss the following points to understand electron dot structure. 

1. What is an electron dot structure?

2. Other names for electron dot structure

3. What information should we get from an electron dot structure?

4. How to draw an electron dot structure?

5. Examples of electron dot structure

 

What is an electron dot structure?

According to Lewis, the symbol of an element represents the nucleus and electrons in the inner shell. The valence electrons are shown by dots (.) or crosses (×).

 

What are the other names of electron dot structures?

  Electron dot structure is also called Lewis structure or Lewis dot structure or Lewis dot formula

 

What information should we get from an electron dot structure?

 

Electron dot structure provides

i.      Visual representation of the molecular structure

ii.     Chemical and physical properties

iii.   Nature of bond

iv.    Position of atoms in molecule

v.       Chemical bonding between atoms in a molecule.

vi.     the total number of lone pairs of electrons

 

How to draw an electron dot structure?

An electron dot structure can be easily written or drawn by following the steps

 

i.       Find the atomic number of each atom in the molecule

ii.    Write the electronic configuration for each atom

iii.  Calculate the total number of valence electrons of the atom present in the molecule

iv.   If the species is an anion, add a number of electrons equal to the units of -ve charge.

v.      If the species is a cation, subtract the number of electrons equal to the units of +ve charge. This gives the number of electrons to be distributed.

vi.     Select the central atom and draw the skeletal structure by intelligent guess to indicate which atom is linked to which other atom.

vii.    Connect the atoms with a single bond

viii.    Put one shared pair of electrons between every two atoms to represent a single bond between them.

ix.       If each atom does not have an octet configuration, then draw   multiple bonding (double or triple bond) to satisfy the octet valency of each atom

x.         Only valence electrons are considered to draw an electron dot structure.

xi.       Electrons are represented by dots or crosses.

Electron dot structure examples class 10

Now we will understand how to write electron dot structure with examples

i.        Electron dot structure of `O_2`

ii.     Electron dot structure of CO

 

Electron dot structure of `O_2`

 Two oxygen atoms combine to form an `O_2` molecule.

   1.   Atomic number of oxygen atoms is 8

   2.   Electronic configuration – `1s^2 2s^2 2p^4`

   3.   Valence electrons in each oxygen atom are 6

   4.   2 electrons are needed to complete the octet configuration

   5.   Each oxygen atom shares two electrons with each other so that a double bond is formed between them

    6.   Skeletal structure of O2

       

    

    7.   Two electrons from each oxygen atom are used in forming a double bond between them and four lone pair electrons for each oxygen atom remain.

      

     Electron dot structure of CO

Carbon monoxide contains one atom of carbon and one atom of oxygen

   1.   Atomic number of oxygen is 8 and atomic number of carbon is 6.

   2.   Electronic configuration of oxygen – `1s^2 2s^2 2p^4`

   3.   Electronic configuration of carbon - `1s^2 2s^2 2p^2`

   4.   Number of valence electrons in oxygen is 6 and  in carbon is 4.

   5.   Carbon atom requires 4 electrons to complete the octet configuration and oxygen requires 2 electrons to complete the octet configuration.

   6.   Skeletal structure of CO

     If one electron is shared by both carbon and oxygen 

      

     In this condition, The octet is not incomplete for both carbon and oxygen.

 

    If two electrons are shared by both carbon and oxygen

    

In this condition, the octet of oxygen is complete [8 electrons] but carbon has 6 electrons yet.

 

If two electrons are shared by a carbon atom and four electrons are shared by an oxygen atom.

   

   

 Now the octet of both carbon and oxygen atoms has been completed. 

Here, a double bond(covalent bond) is formed between carbon and oxygen. But one coordinate bond [bond formed when both two electrons given by one atom and shared by both atoms] is formed.

Now the octet configuration has been achieved.

Related Topics 

1. Formation of Sodium ion

2. Formation of chloride ion

3. Chemical Properties of Metals

4. Physical Properties of Metals

5. Electron dot structure examples