Page 1 - LN
P. 1

SAI International School

                                                     Class – VIII
                                               Subject – Chemistry

                               Topic – Chemical Effects of Electric Current
                  Sub-Topic – Electrodes, Types of Electrodes, Ions and its Types

                                                  LESSON NOTES




        WHAT IS ELECTRICAL CONDUCTIVITY..??


              Electrical conductivity is the ability of a material to conduct electricity.
              Metals are good conductors of electricity. For e.g., Silver, Copper, Aluminium, Iron, etc.

              Non-metals are poor conductors of electricity, except, diamond and graphite. For e.g.,
               Rubber, Plastic, Wood, etc.

              An object or material that allows the flow of electric current is known as Conductor.




        IONS AND ITS TYPES:

              Ion is an atom or a group of atoms having a net electrical charge on them.

              Ions  are  formed  when  the  number  of  protons  in  an  atom  is  not  equal  to  the  number  of
               electrons.

              Ions are formed by the process of Ionization, which is the process of a neutral atom losing or
               gaining electrons.

              If the number of electrons is less than that of the protons, then it is a positive ion. And, that
               particular atom is known as Cations.

              If the number of electrons is more than that of the protons, then it is a negative ion. And, that

               particular atom is known as Anions.


























                                                                                                                1
   1   2