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CBSE Class 7 Science Important Questions Chapter 5 - Physical and Chemical Changes

CBSE

Class 7 Important Question

Science

Chapter 6: Physical And Chemical Changes

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Important Questions for Class 7 Science Chapter 5 Physical and Chemical Changes - FREE PDF Download

Vedantu's Important Questions for Class 7 Science Chapter 5 Physical and Chemical Changes are designed to help students understand the basics of how materials change. This chapter explains what makes a change physical or chemical and explores examples, such as rusting, dissolving, and melting, to show how these transformations affect materials. With straightforward questions, students can practise and clarify key topics in the CBSE Class 7 Science Syllabus.

Our important questions make sure students are well-prepared for exams. Class 7 Science Important Questions provide valuable revision and help students build confidence as they review the main ideas from Chapter 5 on physical and chemical changes. Download the FREE PDF and start learning.

Access Important Questions for Class 7 Science Chapter 5 Physical and Chemical Changes

Very Short Answer Questions (1 Mark)

1. Identify the following changes as physical or chemical.

a. Dissolving sugar in water.

Ans: Physical.

b. Formation of rain from clouds.

Ans: Physical.

c. Formation of acid rain

Ans: Chemical.

d. Combustion

Ans: Chemical.

e. Hammering a nail flat.

Ans: Physical.

Short Answer Questions (3 Marks)

2. What are physical properties? Give examples.

Ans: Physical characteristics are features of a substance that may be determined based on its appearance.

Examples: shape, size, colour, state of compound etc.

3. What are chemical changes? Give examples.

Ans: When one or more compounds react to generate completely new products, this is referred to as a chemical change. The original reactant or substance changes totally as a result of a chemical transformation. The final product is unique. The transformation is irreversible.

Examples: Combustion, corrosion, photosynthesis etc.

4. What are physical changes? Give examples.

Ans: Physical changes occur in a matter that does not result in the creation of a new product. During these transitions, the matter often shifts from one state to another. For example, changes in the state of matter, the solubility of salt and sugar in water, and so on.

5. Explain how burning a strip of magnesium ribbon is a chemical change.

Ans: When magnesium ribbon is burned in the presence of air, it produces white ash with a dazzling white light which is known as magnesium oxide. The ashes formed look physically different in appearance from the initial reactant. It is a chemically unique matter at the same time. Burning magnesium ribbon is an example of a chemical shift because the product is an entirely different compound.

6. What happens when vinegar is added to baking soda? How do you test the gas produced?

Ans: Vinegar is acidic in nature on the other hand baking soda is basic in nature. When we combine these two salts, water along with carbon dioxide gas is formed.

The gas produced is passed through lime water. The lime turns milky or white due to the formation of calcium carbonate. This test confirms the presence of carbon dioxide.

Long Answer Questions (5 Marks)

7. What are the indications of a chemical change?

Ans: The following signs of chemical change are present:

Heat may be absorbed or released in the reaction.
There might be the production of sound during or at the end of the reaction.
A pleasant or pungent odour is created.
A change in the colour of the solution may occur.
Formation of gas.

8. Explain the formation of rust.

Ans: The degrading of metals such as iron in response to the environment is known as rusting. When it comes to oxygen and water, iron is extremely reactive. The production of iron oxide from iron is referred to as rust. It causes the iron article to deteriorate. Rust (Iron III oxide) is formed when iron combines with oxygen and water. Rust starts on the surface and works its way deeper into the metal.

Iron (Fe) + Oxygen (O₂) (from the air) + water (H2O) rust (iron oxide Fe2O3)

9. How can rusting of iron be prevented? Suggest and explain any three methods.

Ans: Rusting is a phenomenon that occurs on the surface of a metal. It can be avoided in the following ways:

Applying oil or grease on the surface inhibits the iron surface from coming into touch with the atmosphere, which prevents rusting.
Galvanization: A layer of a more reactive metal, such as zinc, is deposited on the surface of iron to protect it from rust.
Painting: Applying a layer of paint to the metal's surface stops it from coming into contact with the atmosphere once more.
Alloying: To make alloys, iron can be combined with other metals and non-metals. Rust resistance is a feature of alloys. Stainless steel is an important iron alloy.

5 Important Topics of Class 7 Science Chapter 5 You Shouldn’t Miss!

S.No.	Topics
1.	Physical Changes
2.	Chemical Changes
3.	Rusting of Iron
4.	Crystallisation
5.	Difference between Physical and Chemical Changes

Benefits of Referring to the Important Questions of Class 7 - Physical and Chemical Changes

Students must go through the important questions of each chapter of Science, but why? Some of the reasons for this have been listed below:

These questions help students check their understanding of the chapter and identify any areas they need to improve.
By practising questions beyond the NCERT book, students are ready for challenging questions that might appear in exams.
These questions cover the chapter in detail, making it easier for students to fully understand each topic.
Created by expert teachers, these questions are error-free and follow CBSE standards, so students can trust them for exam prep.
Working through these questions strengthens students' thinking and problem-solving skills, useful for exams and future studies.
Students can download the PDF for free, making it convenient to study offline whenever they want.

Conclusion

Vedantu’s Important Questions for Class 7 Science Chapter 5 on Physical and Chemical Changes are a great way to learn the chapter’s key concepts. This collection of questions focuses on important ideas, such as the differences between physical and chemical changes, examples like rusting, and the process of crystallisation. Practising these questions helps students build confidence and improve their problem-solving abilities. With these questions, learning becomes more engaging, and students can feel prepared to answer various questions related to the chapter. It’s an effective resource for revising and understanding the essentials of physical and chemical changes.

Important Study Materials for Class 7 Science Chapter 5

S.No	Study Materials Links for Chapter 5 Physical and Chemical Changes
1.	Class 7 Physical and Chemical Changes Notes
2.	Class 7 Physical and Chemical Changes Solutions

CBSE Class 7 Science Important Questions for All Chapters

Class 7 Science Important Questions and Answers cover key topics, aiding in thorough preparation and making revision simpler.

S.No	CBSE Class 7 Science Important Questions
1.	Chapter 1 - Nutrition in Plants Questions
2.	Chapter 2 - Nutrition in Animals Questions
3.	Chapter 3 - Heat Questions
4.	Chapter 4 - Acids, Bases and Salts Questions
5.	Chapter 6 - Respiration in Organisms Questions
6.	Chapter 7 - Transportation in Animals and Plants Questions
7.	Chapter 8 - Reproduction in Plants Questions
8.	Chapter 9 - Motion and Time Questions
9.	Chapter 10 - Electric Current and Its Effects Questions
10.	Chapter 11 - Light Questions
11.	Chapter 12 - Forests: Our Lifeline Questions
12.	Chapter 13 - Wastewater Story Questions

Other Important Study Materials for Class 7 Science

S.No	Other Important Study Material for Class 7 Science
1.	Class 7 Science Revision Notes
2.	CBSE Class 7 Sample Papers
3.	NCERT Books for Class 7 Science
4.	NCERT Exemplar for Class 7 Science Solutions

FAQs on CBSE Class 7 Science Important Questions Chapter 5 - Physical and Chemical Changes

1. What are Vedantu's Important Questions for Class 7 Science Chapter 5?

Vedantu's Important Questions focus on main concepts in Chapter 5, like physical and chemical changes. These questions help students understand essential ideas, making it easier to revise effectively.

2. According to Vedantu Important Questions, what are the important topics in the Chapter 5 of NCERT Solutions for Class 7 Science?

Chapter 5 of Class 7 explains the difference between physical and chemical changes. We come across several of these changes but we can hardly notice them. It is important to understand the concepts of physical and chemical changes and the difference between them. It is also crucial that you memorise some of the equations that you can cite as examples in the exam. Understand the process of rusting, galvanization and crystallisation. Make short notes on them. They will come in handy.

3. Explain the process of rusting with the help of an equation in Vedantu’s Class 7 Science Ch 5.

Iron is a meal that is of immense significance. Discovery of iron thousands of years back has revolutionised our way of life. Iron is present in the house we live in, buildings we work or study in, the cars we travel in and our highways and airplanes. Oxygen and water present in the environment reacts with the iron. When the moisture in the air is high, rusting gathers pace. The process of rusting can also be explained by the equation: Iron + Oxygen + Water -> Rusting.

4. What is galvanisation and why is it needed according to Class 7 Science Chapter 5 Physical and chemical Changes?

Galvanization is the process in which a layer of zinc is deposited on iron to prevent it from rusting. A layer of zinc prevents the molecules of oxygen and water from coming in contact with the iron. One can also apply paint or grease. Galvanization is needed because iron is an important part of all of our infrastructures. Rusting destroys the quality of the infrastructure and also weakens it. Rusting causes monetary loss as a huge amount of money is invested in buildings, houses, highways, etc.

5. Do I have to practise questions of Chapter 5 Class 7 Science by Vedantu?

Chapter 5 of Class 7 introduces you to the concept of physical and chemical changes. The concept forms the basis of your higher classes. You will be introduced to several concepts in-depth in your higher classes that will be building upon this chapter’s foundation. Practising questions given in the textbook helps you to analyse how well you have understood the concept. The more questions you practise, the more your understanding will be consolidated. Do not cram the information given. Understand the basics and then practise the questions and revise.

6. How do Vedantu's Important Questions help in understanding physical changes?

Vedantu’s questions on physical changes include examples like melting, freezing, and tearing. These questions guide students in recognising physical changes and understanding their basic characteristics.

7. Does Vedantu Important Questions explain the process of crystallisation in Class 7 Science Ch 5?

Yes, Vedantu’s questions include crystallisation, explaining how crystals form from solutions. This helps students see the practical application of crystallisation in everyday life and science.

8. How does Vedantu explain the importance of preventing rusting in Class 7 Science Chapter 5?

Through questions on rusting, Vedantu highlights prevention methods like galvanisation. These questions show why rust protection is crucial for maintaining the quality of iron materials.

9. What makes Vedantu's Class 7 Science Chapter 5 Important Questions useful for exam preparation?

Vedantu’s questions match NCERT’s exam style, offering targeted practice. This helps students gain familiarity with exam patterns and strengthens their ability to answer questions confidently.

10. Why should students study physical and chemical changes using Vedantu Important Questions?

Vedantu’s Important Questions simplify complex ideas, covering clear examples of both physical and chemical changes. Practising these questions helps students understand the concepts and connect them to real-life scenarios.

11. Why is learning about chemical changes useful through Vedantu’s Class 7 Science Important Questions?

Vedantu’s questions on chemical changes explore how new substances are formed through reactions. This helps students understand the concept of irreversibility and why chemical changes are different from physical ones.