CHEMISTRY|CLASS11|CHEMICAL BONDING2

LEWIS SYMBOLS:

* In this type of formation of a molecule ,only the outermost shell electron are involved ,known as valence electrons.

* The inner shell are not involved in  a reaction. 

 

* G.N.LEWIS used dots to denote electrons.

 *  These dots surrounds symbols of atoms ,these symbols known as Lewis symbols

     for e.g. H . ,He. .

 

 

  IONIC BOND:

*  When a bond is formed by complete transferred of electrons from one atom to  another.so as to  complete their octet ,known as ionic or electrovalent bond.

Lecture1|Class11|Physics|Error analysis

Significant  figure:

Today i am going to provide revision notes on significant figure..which is very significant as the exam point of view...If you have any query related to significant figure write me on comment box,we feel happy to help you...

 

• All non zero digits are significant figure.

  e.g. 2.782 - 4 significant figure. 

         2.36  -  3 significant figure.  

  * All zero between two non zero digits are significant.

     e.g. 2.3008- 5 significant. figure.

            209 -     3 significant. figure.

  * If measurement number less than 1 the zero on the right of  decimal point and to the left of first non zero digit is non significant figure..this point gets more clear with example..

    e.g. 0.00807 -3 significant. figure

           0.008 - 1 significant. figure.

  * Trailing zero without decimal point are not significant.

     e.g. 1230 -  3 s.f.

           12300 - 3 s.f.

  * Trailing zero with decimal point are significant .

     e.g. 12.30-4 s.f.

            3.800-4 s.f.

   

  
  

  
  

  you also visit to lecture2: Error analysis part 2

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  Mrs hope