NCERT Solutions for Class 9 Science Chapter 4 – Structure Of The Atom

NCERT Solutions for Class 9 Science Chapter 4 – Structure of the Atom cover all the fundamental concepts of the chapter. They play a very important role while preparing for the CBSE exams. This chapter deals with topics like Rutherford’s atomic model, Bohr’s atomic model and parts of an atom. 

CBSE Class 9 NCERT Chapter 4 – Structure of the Atom, has 6 exercises and 37 questions in total. The chapter of NCERT Solutions for Class 9 consists of various kinds of questions. NCERT Solutions for Chapter 4 – Structure of the atom, will help you develop a strong understanding of the various aspects of an atom along with the terms and theories revolving around it. 

CBSE Chapter 4 – Structure of the Atom offers basic insight into the study of atoms. It covers terms like electrons, the valency of an electron, isotopes, isobars, electronic shells, orbits of an atom etc. The chapter has a lot to offer for building the foundation of knowledge about atoms and its intricate details. Given below is a short description of the chapter.

Important Topics of NCERT Class 9 Science Solution Chapter 4 – Structure of an Atom

Thompson’s Atomic Model

The chapter talks about the atomic model which was presented by scientist J.J. Thompson. He proposed his theory that atoms comprise of a positively charged sphere which has electrons attached to it. The chapter explains the shortcomings of the model as well as the role it played as the foundation for further studies about atoms. 

Rutherford’s Atomic Model

The chapter also includes the atomic model which was proposed by Rutherford. According to his atomic model, an atom comprised of particles which are positively charged and are concentrated at the centre of the atom. This centre of the atom is known as the nucleus. He further explained that in comparison to the size of the atom the nucleus is very small. He also found out that the electrons revolve around the nucleus in fixed paths which are known as orbits. 

Bohr’s Atomic Model 

A scientist named Neils Bohr also came up with his theory of atomic models. According to his study, there were certain orbits which were known as discrete orbits and the electrons revolved around the nucleus in these orbits only. He also stated that there was no radiation of energy by the electron while they revolved.  

Rules for the distribution of electrons 

The chapter introduces you to the basics of analyzing the distribution of electrons in the various shells of the atom for the first eighteen elements of the periodic table. The following rules about the same are discussed in the chapter –

  • A shell can accommodate a maximum of 2n electrons. Here ‘n’ denotes the orbit number of the energy level index.
  • There can only be eight electrons in the outermost orbit. 
  • Electrons are accommodated on the orbits in a stepwise manner. First, the inner shells are filled and then the remaining electrons get to the outer shells. 

Exercise wise discussion of Class 9 Solutions Chapter 4 – Structure of the Atom

Science NCERT Class 9 Chapter 4 – Structure of the atom comprises of diverse categories of questions. These questions test your analysis and application skills and also brush up the fundamentals which you pick from the chapter. There are reasoning questions, questions based on the comparison, numerical, short answer questions, definitions etc. 

The first exercise of NCERT Class 9 chapter 4, begins with a short answer question that asks for the definition of ‘Canal rays’. Further, there are questions that test your understanding of the concepts of charge and atomic structure. 

There are questions which require detailed information about the different atomic models like the comparison between, Thompson, Bohr and Rutherford in terms of their atomic theories. 

There are questions which ask you to give the electronic configuration of different elements based on their number of electrons. The chapter also has numerical problems which deal with the percentage of isotopes and isobars, average atomic mass, the valency of the elements and their mass number. 

About NCERT Class 9 Chapter 4 – Structure of the Atom by Instasolv

  • All the NCERT Solutions for Class 9 Science Chapter 4 – Structure of the Atom are given in a detailed and step by step manner, to ensure that you understand every point and accordingly apply it while answering your exams in future. 
  • Once you engage with our study material, you will not only get a thorough practice of the chapter but will also brush up your analytical and problem-solving skills. 
  • We have the best science teachers of India who prepare the NCERT solutions for class 9 
  • They make sure that you get enough confidence to answer any kind of question which can be framed from the chapter. 
  • We have adhered to the latest CBSE syllabus while formulating the answers. You can completely rely on our answers without the fear of going against the pattern laid down by the CBSE board. 
  • The best thing about our NCERT Solutions for Class 9 Science Chapter 4 – Structure of the Atom, is that it does not even cost you a penny! These solutions by Instasolv are free of cost.