NCERT Solutions for Class 9 Science Chapter 4


NCERT Solutions for Class 9 Science Chapter 4, solutions are available in free PDF format. CoolGyan, supply students with the perfect formula to erase all their exam preparation woes. These study materials are updated as per the syllabus for 2019-20, integrates the importance of Science Chapter 4 in a student’s curriculum and allows them to develop their analytical and problem-solving skills. One can download NCERT Solution PDF to learn how to formulate comprehensive answers and score the subject-best grades. Subjects like Science, Maths, English will become easy to study if you have access to NCERT Solution for Class 9 Science , Maths solutions and solutions of other subjects. You can also download NCERT Solutions for Class 9 Maths to help you to revise complete syllabus and score more marks in your examinations.



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

Science Chapter 4 from Class 9 syllabus forms a part of the book’s first unit – Matter – Nature, and Behaviour. Taking into account the convenience of students, the exercises that follow are bifurcated into multiple Intext exercises and an NCERT exercise. Since both are deemed important for exams, our solutions cover both these types of questionnaires.


Following is an overview of questions provided in our NCERT Solutions for Class 9 Science Chapter 4 PDF that can aid students to succeed in their endeavors to score better.


A. Science Chapter 4 – Intext Questionnaire


1) Class 9 Science Chapter 4 – Exercise 1: There are two questions under this particular exercise pertaining to the sub-topic of ‘Charged Particles in Matter’. These questions require students to study and understand the chapter from their CBSE NCERT books to formulate proper answers – 


Question 1 – It is a fairly straightforward question and asks students to define canal rays. The Science Chapter 4 solution to this question in our PDFs lets you know how to frame the answer in a crisp and concise fashion.


Question 2 – It takes students back to the basics and requires them to explain if an atom containing one proton and one electron will carry a charge or not.


2) Class 9 Science Chapter 4 – Exercise 2: This exercise of Class 9 Science Chapter 4 question answer tests students’ knowledge of three significant topics – Thomson’s Model, Rutherford Model and Bohr’s Model of an Atom. Students can gauge their preparation of these topics from Science Chapter 4 by looking up the answers to the following four questions – 


Question 1 – With this question, students will be required to give an account of an atom’s neutrality, adhering to Thomson’s model.


Question 2 – To answer this one about the Rutherford Model of an Atom, one will have to have a clear concept of this topic from their NCERT books PDF. Here, this question asks students to identify which subatomic particle is present in an atom’s nucleus.


Question 3 – Here, students will have to illustrate the Bohr’s model of an atom with proper labeling of its parts. 


Question 4 – This question from NCERT Solutions for Class 9 Science Chapter 4 Exercise aids students to encapsulate their observations of an α-particle scattering experiment.


3) Class 9 Science Chapter 4 – Exercise 3: This exercise from Science Chapter 4 contains two questions whose answers have been curated by experts in our NCERT Solutions. These are as follows – 


Question 1 – This one tests a student’s basic knowledge of the subject by asking them to identify the three sub-atomic particles in an atom.


Question 2 – This is numerical where one will have to calculate the number of neutrons in a Helium atom. Students can tally the answer they derive against the one provided in the Science Chapter 4 solution to evaluate their exam preparation. 


4) Class 9 Science Chapter 4 – Exercise 4: There are two questions under this exercise where students are required to show step by step calculations to the sums. These questions are as follows – 


Question 1 – Here, students are required to put down the distribution of electrons in sodium and carbon atoms.


Question 2 – With this question, students will have to calculate the total number of electrons present in an atom, in case its K and L shells are full.


5) Class 9 Science Chapter 4 – Exercise 5: There is a single question under this exercise where one has to calculate the valency of Magnesium, Sulphur, and Chlorine. Our Structure of Atom Class 9 NCERT Solutions PDF can be helpful in this respect. 


6) Class 9 Science Chapter 4 - Exercise 6: Exercise 6 of this chapter consists of these following questions which test a student’s knowledge about atomic and mass number – 


Question 1 – Here, students are required to identify the atomic number of an atom that has the same number of protons and electrons and calculate their charge. 


Question 2 – To answer this question, one will have to gather an adequate knowledge of the “mass number of sulphur and oxygen atom”. Chapter 4 Science Class 9 can help out in this regard.


7) Class 9 Science Chapter 4 - Exercise 7: There are two questions under this exercise from the sub-topics ‘Isotopes and Isobars’ of this chapter. As per the syllabus, these topics from NCERT books PDF hold critical importance in a student’s curriculum, making the questions all the more crucial. 


Question 1 - Here, students are required to tabulate three sub-atomic particles for the symbols H, D, and T.


Question 2 – In this question from Structure of Atom Class 9 students will be required to pen down the electronic configuration of a single pair of Isobars and Isotopes. Our NCERT Solution for this question can help students know how to pen down the answer to this question in a comprehensive manner.


B . Class 9 Science Chapter 4 - NCERT Exercise


There are 19 more questions from this chapter under the NCERT exercise, which will test the students’ knowledge of its various aspects. It includes topics that include 


-Charged particles in matter,

-Atomic number, 

-Structure of an atom,

-Isotopes/isobars, etc.


It is pertinent for one to understand how to formulate the answer to each of these questions from NCERT books online. However, students should pay special attention to out of the box questions like numbers 4, 5, 13 and 19. These ask students to


-complete tables, 

-compare atomic models, 

-calculate isotope percentages, etc. 


With our NCERT Solutions, students no longer have to approach Science with a grain of salt. Our solutions are potent enough to make your exam preparation a lot more well-rounded.


You can also Download NCERT Solutions for class 9 Maths to help you to revise the complete Syllabus and score more marks in your examinations.


CoolGyan – The Perfect Guide to Score Better in Exams!

We, at CoolGyan, work towards a single goal – to streamline exam preparations for students through comprehensive NCERT solutions of each chapter of a subject. With our Science Chapter 4 solutions, one can not only learn how to formulate the perfect answers but also, gain an in-depth knowledge of the subject. 


It is because our solutions to the NCERT books download are curated by subject-experts who pay special attention to making the answers well-rounded for any student’s benefit. Additionally, the online PDF format of our solutions, available for free, allows students to carry our study materials anywhere according to their convenience.


Further, we have also introduced one-on-one online classes with experienced teachers to facilitate problem-solving sessions with students. 


So what are you waiting for? Refer to our solutions today for better exam preparations!