NCERT Solutions for Class 9 Science, Chapter 4 - Structure of the Atom

In the previous chapter, you got a clear idea of what atoms and molecules are. You
are aware of the fact that whatever matter we see around is composed of different
atoms found in them. An atom is nothing, but the tiniest unit of matter possessing
all the chemical properties of an element. In this chapter, you’ll answer questions
such as – why the atoms of one element are different from the atoms of another
element. You’ll also study the structure of atoms as described by various scientists.
Besides, you’ll learn what valency is, atomic number, mass number, isotopes and
isobars.

In-depth knowledge of NCERT Solutions for Class 9, Chapter 4 will help you
clearly, understand the Structure of an Atom.

Let’s take a look at topics and sub-topics of Class 9 Science Chapter 4, Structure of the Atom

4.1 Charged Particles in Matter
4.2 The Structure of an Atom
4.2.1 Thomson’s Model of an Atom
4.2.2 Rutherford’s Model of an Atom
4.2.3 Bohr’s Model of Atom
4.2.4 Neutrons
4.3 How are Electrons Distributed in Different Orbits (Shells)?
4.4 Valency
4.5 Atomic Number and Mass Number
4.5.1 Atomic Number
4.5.2 Mass Number
4.6 Isotopes
4.6.1 Isobars

In Class 9 Science Chapter 4, you will learn – 

Section 4.1 – In this section, you’ll study the charged particles in the matter. You’ll
learn what atoms are composed of, what are canal rays, what sort of structure the
particles of the atom formed and more.

Section 4.2 – In this section, you’ll acquire knowledge about the structure of an
atom in detail as proposed by various scientists. You’ll also learn about the atomic
models as proposed by J.J. Thomson, followed by Rutherford’s Model and BOHR’S
Model of Atom and their limitations. You’ll also come across neutrons in this
section.

Section 4.3 – In this section, you’ll study the distribution of electrons into different
orbits of an atom as proposed by Bohr and Bury. You’ll also learn about the rules
followed while writing the number of electrons in various energy levels or shells
and the atomic structure of the first eighteen elements schematically.

Section 4.4 – In this section, you’ll learn what valency is and the composition of
atoms of the first eighteen elements with electron distribution in different shells.

Section 4.5 – In this section, you’ll study what is the atomic number and mass
number.

Section 4.6 – In this section, you’ll acquire knowledge about isotopes, properties
and applications of isotopes.

In this chapter, you are provided with several diagrams, activities and examples
with their solutions for a clear understanding of the Structure of the Atom. To
know more about NCERT Solutions for Class 9 Chapter 4 you should explore the
exercises mentioned in this chapter. You can also download the Structure of the
Atom Class 9 Solutions PDF, solved by our science experts.