Chapter 4

NCERT
Class 9
Science
Solutions
5. Compare all the proposed models of an atom given in this chapter.

Question:

Compare all the proposed models of an atom given in this chapter.

Answer:

Thomson’s atomic model Rutherford’s atomic model Bohr’s atomic model
No explanation about
nucleus
Nucleus is explained Nucleus is explained
The positive charge exists
in the form of a sphere.
A positive charge, called
proton, is present inside the
nucleus.
A positive charge called proton is
present inside the nucleus.
Electrons are studded in a
positively charged sphere
Electrons keep revolving
around the nucleus in orbits.
Electrons keep revolving in fixed orbits.
(in energy levels) around the nucleus.
This is a nuclear model Rutherford’s model had many
drawbacks.
Bohr improved Rutherford’s model.

Buy Latest Books

Teacher's Corner