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CBSE Class 7 Science Chapter 5 Physical and Chemical Changes Revision Notes

Revision Notes

Class 7

Science

Chapter 6 Physical And Chemical Changes

Class 7 Science Chapter 5 Physical and Chemical Changes Revision Notes- Free PDF Download

Physical and Chemical Changes Chapter 5 Notes PDF is available here for free download of the CBSE Class 7 students. This PDF comprises notes which will help the CBSE Class 7 students to prepare and revise the chapter on Physical and Chemical Changes for their Science exams thoroughly.

Students preparing for their Class 7 science examination are encouraged to refer to the NCERT Class 7 Science Chapter 5 Notes that are designed by our subject experts at Vedantu. The Class 7 Science Chapter 5 Notes PDF is available for download from our official website and Vedantu mobile app allowing students to learn in a convenient environment. Download NCERT Solutions PDF and opt to refer to the questions and answers to score good marks. You can also download NCERT Solutions for Class 7 Maths to revise the complete syllabus and score more marks in your examinations.

Download CBSE Class 7 Science Revision Notes 2024-25 PDF

Also, check CBSE Class 7 Science revision notes for other chapters:

CBSE Class 7 Science Chapter-wise Notes
Chapter 1: Nutrition in Plants Notes	Chapter 2: Nutrition in Animals Notes
Chapter 3: Fibre to Fabric Notes	Chapter 4: Heat Notes
Chapter 5: Acids, Bases and Salts Notes	Chapter 6: Physical and Chemical Changes Notes
Chapter 7: Weather, Climate and Adaptations of Animals to Climate Notes	Chapter 8: Winds, Storms and Cyclones Notes
Chapter 9: Soil Notes	Chapter 10: Respiration in Organisms Notes
Chapter 11: Transportation in Animals and Plants Notes	Chapter 12: Reproduction in Plants Notes
Chapter 13: Motion and Time Notes	Chapter 14: Electric Current and Its Effects Notes
Chapter 15: Light Notes	Chapter 16: Water: a Precious Resource Notes
Chapter 17: Forests: Our Lifeline Notes	Chapter 18: Wastewater Story Notes

Access Class 7 Science Chapter 5 - Physical and Chemical Changes

Physical and chemical changes are the two sorts of changes that might occur.

Physical alterations refer to changes in a substance's physical qualities. These alterations do not result in the formation of any new compounds. These modifications might be reversible. Crushing a can, lighting an electric bulb, ripping paper, and mixing sand and water are just a few examples.
Chemical alterations occur when the substance's composition and chemical characteristics are altered. New chemicals are created as a result of chemical reactions. This is a permanent and irrevocable transformation. For instance, a candle is lit, the curd is formed from milk, and fruits ripen.

Chemical Reactions in the Real World:

Iron Rusting: Iron rusting is the transformation of iron into iron oxide. When iron comes into touch with water and oxygen, something happens. The process is a sort of corrosion that happens frequently in nature.

Prevention of Rusting:

i. By Painting

ii. By Oiling and greasing

iii. By Chromium plating

iv. By Galvanizing

v. By Alloying

Cooking of Food: Cooking breaks down complex carbs, lipids, and protein molecules into smaller molecules.

It's thought to be a breakdown process. Food that has been prepared is easier to digest than food that has not been cooked.

Decay of Organic Substances: Enzymes are produced by microorganisms such as fungi and bacteria, which break down complex chemical materials into simpler components. It's also referred to as a breakdown process.

Crystallization can be used to obtain pure compounds from their solutions.

Benefits of Physical and Chemical Changes Chapter 5 (Class 7) Science Revision Notes

Check out the benefits of Chapter 5 Class 7 Science Revision Notes below.

Class 7 Science Chapter 5 revision notes will function as a great reference tool for the students to strengthen their understanding and revision of the important concepts of the chapter.
Students will become more confident about solving even the complex questions of the chapter during the exam.
Exam stress and anxiety will therefore be greatly reduced.
The revision notes will enable students to revise their chapters quickly and efficiently without compromising on the quality of preparation.
The revision notes are prepared in a concise manner, thus the students can revise from these notes a day before the exam when time is limited and the chapters to study are vast.
The revision notes are in a convenient pdf form, this will help the students to study these revision notes from anywhere and at any time.

Topics Covered in Physical and Chemical Changes Chapter 5 (Class 7) Science

Following are the topics represented in the tabular form which are covered in Class 7 Chapter 5 Science.

Section Name	Topic Name
5	Physical and Chemical Changes
5.1	Physical Changes
5.2	Chemical Changes
5.3	Rusting of Iron
5.4	Crystallisation

Physical and Chemical Chapter 5 Class 7 Science - Key Takeaways of the Chapter

Physical Changes: During a physical change, substances go through changes only in its physical properties like size, colour, state, and shape. Most importantly, no new substance is generated in these changes. To understand the topic, it is essential to perform a few activities and see how physical changes take place around us. Generally, all the physical changes are momentary changes that can easily be reversed to create the original substance. If there is little energy as heat, it is either absorbed or evolved. For example, water can change its state from solid to liquid and liquid to gas.

Crystallisation: As seawater has salts dissolved in it, the sea becomes salty. Salt can be acquired from seawater by a procedure called evaporation. The salt acquired in this way is not pure, and its crystals are tiny. The shape of the crystals can’t be seen clearly. However, giant crystals of pure substances can be acquired from their solutions by the process of crystallisation.

The method of cooling a hot concentrated solution of a substance to acquire crystals is known as crystallisation. It is a primary example of a physical change.

Chemical Changes: The Class 7 Science CH 5 Notes include chemical changes, which are also widely referred to as chemical reactions. A chemical change happens when two substances react chemically to generate a new substance with totally different chemical properties. All these new substances that we utilize in multiple fields of our life are generated due to chemical changes or chemical reactions.

Let’s take a look at an example of chemical changes. A change with which almost everyone is familiar is the rusting of iron. All the iron or steel items kept in the open space or area get rusted slowly. It develops a coating of a brownish substance known as rust, and the procedure is known as rusting. Usually, we see iron gates of farms and parks, iron benches kept in gardens, and almost all the iron items kept in the open space rusted with time. Other things, like agricultural tools, kitchen tools, etc., also get rusted. Rust is not iron; it is a different substance but gets deposited on iron.

Rusting of Iron: When an iron item is left exposed to a moist environment, it chemically reacts with oxygen and water in the air to generate a red-brown flaky substance known as rust. The following equation can represent the procedure of rusting:

Iron (Fe) + Oxygen (O₂) (From air) + Water (H₂O) → Rust (Iron oxide, Fe₂O₃)

Rusting happens due to the presence of both water and oxygen. The more humid the environment, the quicker the rusting happens. The rust slowly eats away or corrodes the iron, resulting in considerable loss. As iron is utilized in building ships, cars, bridges, truck bodies, and various other items, the temporary loss because of the rusting is massive.

Chapter-wise Revision Notes for Class 7 Science

Also Access,

CBSE Class 7 Science Revision Notes for all the other chapters are also available for free download on Vedantu’s official website. These revision notes will help you during your last-minute exam preparation to cover all the important topics of the chapters. To access CBSE Class 10 Science NCERT Solution, Important Questions, and other study-related materials, visit Vedantu.com.

Importances of CBSE Class 7 Science Chapter 5 Physical and Chemical Changes Revision Notes

The importance of CBSE Class 7 Science Chapter 5 - "Physical and Chemical Changes Revision Notes" cannot be overstated. These notes play a crucial role in students' academic journey by providing a succinct yet comprehensive recap of the chapter's key concepts. They serve as an invaluable revision tool, helping students consolidate their understanding of physical and chemical changes in matter. Furthermore, these notes are instrumental in exam preparation, allowing students to focus on essential topics and concepts. They promote efficient study habits, time management, and self-assessment, ultimately enhancing the learning process. Overall, these revision notes are an indispensable resource that empowers students to excel in their science studies while fostering a deeper appreciation for the intriguing world of chemistry.

Conclusion

CBSE Class 7 Science Chapter 5 - "Physical and Chemical Changes Revision Notes" are a valuable resource for students embarking on a journey through the intriguing world of chemistry. These notes offer a concise and comprehensive overview of the chapter, elucidating the distinctions between physical and chemical changes. They serve as a vital tool for revision, aiding students in consolidating their understanding of chemical transformations and their practical implications. Moreover, these revision notes foster critical thinking and problem-solving skills, preparing students to excel in examinations and develop a lasting appreciation for the fascinating realm of science.

FAQs on CBSE Class 7 Science Chapter 5 Physical and Chemical Changes Revision Notes

1. What are the Significant Characteristics of a Chemical Change?

The main characteristics of a chemical change are as follows:

They release or absorb energy.
Single or more new substances with different properties are generated.
Generally, most of the changes that occurred are irreversible.
The properties of items are majorly different from the reactants.

2. Nearly all of the Physical Changes are Reversible, but a Few are Irreversible. Explain the Statement with Some Examples.

In a physical change, substances change their physical properties only. This change happens when there is some kind of force applied like, change in temperature, shape, etc., on a particular substance. The majority of the physical changes are reversible, like rolling dough into a chapati and then again bringing back into a dough.

3. What is the Iron Pillar in Qutub Minar Located in Delhi Famous for?

It is famous as it has not rusted though it was constructed more than 1600 years ago.

4. What are the important topics in Chapter 5 of NCERT for Class 7 Science?

Chapter 5- Physical and Chemical Changes of CBSE Class 7 Science begins with an introduction about what are the physical and chemical changes and their examples in our day to day lives. The next important topic covered in this chapter is the characteristics of the physical and chemical changes. An in-depth analysis of the mechanism behind the rusting of iron and its prevention is discussed next. Then, the chapter concludes with the topic- crystallisation.

5. What are the best revision notes for Chapter 5- Physical and Chemical Changes of NCERT Class 7 Science?

The best revision notes for Class 7 Science, Chapter 5- 'Physical and Chemical Changes' are CBSE Class 7 Science Chapter 5 Revision Notes. These notes are the best quality notes and are 100% credible as they are based on the latest CBSE syllabus and exam pattern. These notes are compiled by a team of the best Science teachers in India with decades of experience in teaching. Studying from these notes will greatly simplify your Science exam preparation and will help you obtain a better conceptual understanding.

6. What are the physical changes according to Class 7 Science?

As discussed in the chapter, a physical change is a change that alters the physical properties (shape and size) of a substance without any alteration in the chemical properties. In simple words, physical change doesn't lead to the formation of any new substance and it is usually a reversible change. For instance, the melting of ice is a physical change because it involves a change in the physical properties (solid ice to liquid water), it is a reversible change and no new substance is formed.

7. What are the chemical changes according to Class 7 Science?

As discussed in the chapter, a chemical change is the complete opposite of physical change. A chemical change is a change that involves a change in the chemical properties of a substance and leads to the formation of one or more new substances, and it is usually an irreversible change. For instance, the burning of wood is a chemical change because a new substance, ash is being formed and ash cannot be reversed back to wood.

8. Can you please provide some tips to get good marks in Chapter 5- Physical and Chemical Changes of CBSE Class 7 Science?

To get good marks in Chapter 5- Physical and Chemical Changes of CBSE Class 7 Science,read the chapter from the NCERT standard textbook carefully. Aim for an in-depth understanding of the chapter by referring to NCERT and Vedantu notes. Clear all your doubts with the help of Vedantu's Revision Notes for this chapter. Practise all the questions given in the NCERT and solve previous year questions to strengthen this chapter. Most importantly, revise the syllabus as much as possible to perform well in the Science exam.