NCERT Solutions for Class 9 Science Chapter 3 Atoms and Molecules

NCERT Solutions for Class 9 Science Chapter 3 - Atoms and Molecules: The idea of divisibility of matter was considered long back in India, around 500 BC. An Indian philosopher Maharishi Kanad, postulated that if we go on dividing matter (padarth), we shall get smaller and smaller particles. Ultimately, a stage will come when we shall come across the smallest particles beyond which further division will not be possible. He named these particles Parmanu. Another Indian philosopher, Pakudha Katyayama, elaborated this doctrine and said that these particles normally exist in a combined form which gives us various forms of matter. You will study that Antoine L. Lavoisier laid the foundation of chemical sciences by establishing two important laws of chemical combination which you are going to study in this chapter.

Here are the important Topics of NCERT Solutions for Class 9 Science Chapter 3 - Atoms and Molecules mentioned below:

3.1 Laws of Chemical Combination

3.1.1 Law of Conservation of Mass

3.1.2 Law of Constant Proportions

3.2 What Is an Atom?

3.2.1 What Are the Modern Day Symbols of Atoms of Different Elements?

3.2.2 Atomic Mass

3.2.3 How Do Atoms Exist?

3.3 What Is a Molecule?

3.3.1 Molecules of Elements

3.3.2 Molecules of Compounds

3.3.3 What Is an Ion?

3.4 Writing Chemical Formulae

3.4.1 Formulae of Simple Compounds

3.5 Molecular Mass and Mole Concept

3.5.1 Molecular Mass

3.5.2 Formula Unit Mass

3.5.3 Mole Concept

In Class 9 Science Chapter 3 - Atoms and Molecules, you will also study that during a chemical reaction, the sum of the masses of the reactants and products remains unchanged. This is known as the Law of Conservation of Mass. In a pure chemical compound, elements are always present in a definite proportion by mass. This is known as the Law of Definite Proportions. An atom is the smallest particle of the element that cannot usually exist independently and retain all its chemical properties

After going through this chapter, you must be able to get the NCERT Solution of these questions which are mentioned below, as these questions are from NCERT.

Q1. A 0.24 g sample of a compound of oxygen and boron was found by analysis to contain 0.096 g of boron and 0.144 g of oxygen. Calculate the percentage composition of the compound by weight.

Q2. When 3.0 g of carbon is burnt in 8.00 g oxygen, 11.00 g of carbon dioxide is produced. What mass of carbon dioxide will be formed when 3.00 g of carbon is burnt in 50.00 g of oxygen? Which law of chemical combination will govern your answer?

Q3. Calculate the number of molecules of sulphur (S8 ) present in 16 g of solid sulphur.

If you have any problem in answering these questions or you are not getting the correct answers then don't worry, NCERT Solutions for Class 9 Science Chapter 3 - Atoms and Molecules is there for you to help. Solutions for NCERT Class 9 Science Chapter 3 - Atoms and Molecules will give you answers to all the questions which are mentioned in the NCERT book.

First of all, try to answer all the questions by yourself. Then, if you need any help, NCERT Solutions for Class 9 Science Chapter 3 - Atoms and Molecules will suggest you the best answer written by our experts.

NCERT Solutions for Class 9 Science- Chapter Wise

 Chapter No. Chapter Name Chapter 1 Matter in Our Surroundings Chapter 2 Is Matter Around Us Pure Chapter 4 Structure of The Atom Chapter 5 The Fundamental Unit of Life Chapter 6 Tissues Chapter 7 Diversity in Living Organisms Chapter 8 Motion Chapter 9 Force and Laws of Motion Chapter 10 Gravitation Chapter 11 Work and Energy Chapter 12 Sound Chapter 13 Why Do We Fall ill? Chapter 14 Natural Resources Chapter 15 Improvement in Food Resources