Students already have some knowledge about atoms, molecules, chemical symbols and Dalton’s Atomic Theory.

Q1) Can you tell which postulate of Dalton relates to law of constant proportion?

Q2) Derive some chemical symbol from their charges: -

(a)   Sodium Chloride                       (b) Aluminium Sulphate

 Q3) Can you categorize Argon, Phosphorus, Oxygen and Sulphur on the basis of their atomicity?

Topics to be covered in this chapter:

   Brief description of John Dalton’s Atomic Theory; Discovery of electrons, protons and neutrons;   Describing the Structure of an Atom according to different models such as: -

(a)   Thomson’s Model Of An Atom (Postulates and Drawbacks)

(b)   Rutherford’s Model Of An Atom (Postulates and Drawbacks)

(c)    Bohr’s Model of Atom (Postulates)

Valency and Valence Electrons; Electronic Configuration (first 20 elements), Schematic diagram of atomic structure; Atomic number and Mass number; Isotopes, Isobars and isotones.

⁎ Students will be able explain the detail description of the structure of an atom and understand the concept of electrons, protons and neurons

       ⁎ They will be able to distinguish between all the models of the structure of atom.

       ⁎ They will be able to write the electronic configuration and valence electrons and valency of the first 20 elements. 

       ⁎ They will be able to draw the schematic diagram of the atomic structure of an atom

       ⁎ They will be able to distinguish between isobars , isotopes and isotones.