Ncert Solutions for Class 9 Science Chapter 3 Atoms and molecules

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NCERT Solutions for Class 9 Science Chapter 3- Atoms and Molecules is a comprehensive study guide written by professionals. It contains the answers to the textbook’s questions. For a better comprehension of topics and self-analysis, NCERT Solutions are really useful.

The solutions cover questions from all of the topics. Everything is provided in an easy-to-understand manner for students. It will assist students in achieving a high score on the CBSE Term II examination. The NCERT Solutions for Class 9 Science provide answers to a variety of long and short problems, MCQs, tricks, and hints. After you’ve finished the full curriculum, try answering the questions to see if you can spot any flaws before the CBSE Term II exams.

Because the chapter Atoms and Molecules is the foundation for the following chapters, it should be thoroughly covered. The questions and answers will assist students in resolving any doubts they may have about the subject.

All of the relevant questions and answers for all of the subjects and chapters are included in the NCERT Solutions for Class 9. Students can use these solutions to help them succeed in the CBSE Term II exams.

ATOMS AND MOLECULES

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

A. The mass of sample of compound = 0.24g

The mass of Boron = 0.096g

The mass of Oxygen = 0.144g

Percentage of Boron in the sample = = 0.4 × 100 = 40

Percentage of Oxygen in the sample = = 0.6 × 100 = 60

The sample of compound contains 40% Boron and 60% Oxygen by weight.

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

Ratio by mass of Carbon and Oxygen in Carbon dioxide is 3 : 8 that means 3g of Carbon combining with 8g of Oxygen to give 11g of Carbon dioxide. According to law of constant proportions in the second case also 3g of Carbon must combine with 8g of Oxygen to give 11g of Carbon dioxide. This means that

(50 – 8) g = 42g of Oxygen will remain unreacted. This indicates law of definite proportions which say that in compounds, the combining elements are present in definite proportions by mass.

(Hint : The mass of an ion is the same as that of an atom of the same element, Atomic mass of Al = 27U)

1 Mole of Al2O3 = 2 × 27 + 3 × 16 = 54 + 48 = 102g

1 Mole of Al2O3 has = 2 mole Al+3 ions

i,e; 102g of Al2O3 has = 2 mole Al+3 ions

102g of Al2O3 has = 2 × 6.022 × 1023 Al+3 ions

then 0.051g of Al2O3 has = ?

= =

0.051g of Al2O3 has = 6.022 × 1020 Al + 3 ions

NCERT Solutions for Class 9 Science Chapter 3

An atom is the smallest unit of matter. It possesses the characteristics of an element. A nucleus is a compact centre surrounded by a succession of surrounding shells that make up an atom. These shells have electrons in them. Protons and neutrons are found in the nucleus. Neutrons have a neutral charge, while protons have a positive charge.

A molecule is made up of two or more atoms that are securely bonded together. Diatomic molecules are those that are made up of two atoms. Diatomic molecules include oxygen, nitrogen, hydrogen, and iodine. The diatomic molecules make up the majority of the Earth’s atmosphere. The smallest component of a substance is a molecule.

 

NCERT Solutions for Class 9 Science Chapter 3: Atoms and Molecules: Important key

1. Experts in science supply the answers.

1. None of the responses are incorrect.

1. The Solutions include questions on every major subject.

1. It provides in-depth knowledge of the subjects.

NCERT Solutions for Class 9 Science: Frequently Asked Questions 3rd Chapter

Indicate the areas enclosed in NCERT Solutions for Class 9 Science, Chapter 3.

The following subjects are covered in Chapter 3 of NCERT Solutions for Class 9 Science:

3.1 Chemical Combination Laws

3.2 What is the definition of an atom?

3.3 What is the Definition of a Molecule?

3.4 Formulae for Chemicals

3.5 Mole Concept and Molecular Mass

How can you tackle the numerical in Chapter 3 of NCERT Solutions for Class 9 Science more quickly?

Students in Class 9 should solve the numerical in the NCERT textbook to have an understanding of the important formulas. If students have any difficulties with how to do the exercise problems, they can consult the NCERT Solutions for Class 9 Science from INFINITY LEARN’S, which contains detailed solutions to each problem. The solutions provide step-by-step explanations to ensure that students understand how to solve issues without trouble.

What distinguishes NCERT Solutions for Class 9 Science Chapter 3 from others?

The following are the main aspects of NCERT Solutions for Class 9 Science Chapter 3:

1. The solutions have been prepared by highly qualified scientists.
2. The solutions are correct and error-free, and they are based on the most recent CBSE syllabus.
3. Every major topic is taught in easy-to-understand language to assist pupils to succeed in the CBSE Term II exams.
4. Using INFINITY LEARN’S NCERT Solutions, students gain a solid comprehension of the key ideas.

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