Question

experimental study chemistry class 9 ICSE chapter 3

Answer 1

JJ Thomson conducted experiments and gave the structure of an atom
J.J. Thomson proposed that electrons are embedded in a positive sphere. 
Rutherford’s alpha-particle scattering experiment led to the discovery of the atomic nucleus. Rutherford’s model of the atom proposed that a very tiny nucleus is present inside the atom and electrons revolve around this nucleus. The stability of the atom could not be explained by this model.
J. Chadwick discovered presence of neutrons in the nucleus of an atom. 
So, the three sub-atomic particles of an atom are: (i) electrons, (ii) protons and (iii) neutrons.
Learn other interesting topics like: distribution of electrons in an atom (electronic configuration), valency, atomic number, atomic mass, isotopes and isobars.

View Lessons & Exercises for Modern Atomic Model → View Lessons & Exercises for Electronic Configuration in an Atom →View Lessons & Exercises for Ionic Compounds →