Category: 9th Science

  • Chemistry IX | Structure of Atom | Part 2

    Structure of Atom | Part 2 I. Thomson’s Atomic Model The first simple model of an atom was proposed by J.J. Thomson. According to this model an atom consists of a uniform sphere (radius approx 10 – 10 m) of positive charge with electron embedded in such a way so as to give most stable…

  • Chemistry IX | Structure of Atom | Part 1

    Structure of Atom | Part 1 INTRODUCTION Atom is the smallest particle of an element, does not found in free state but takes part in chemical reaction. Main Postulates of Dalton’s Atomic Theory All matter is made up of very small particles known as atoms. Atom can neither be created nor destroyed, it is the…