NCERT Solutions For Class 7 Science Chapter 6: Physical And Chemical Changes

NCERT Solutions for Class 7 Science Chapter 6 - Physical and Chemical Changes - Division of the Chapter 6

NCERT Solutions for Class 7 Science Chapter 6 - Physical and Chemical Changes are provided in this article. Further, if you want to know about the division of Chapter 6, which will help you plan and strategise your study beforehand, you must definitely read the following breakup of the chapter: 

• Physical and Chemical Changes, Chapter 6 of NCERT Grade 7 Science, is broken into four sections for easier comprehension. 

• The chapter opens with several instances of changes that occur every day in our environment. 

• The first section employs five distinct tasks to explain what the word "physical changes" means. 

• The qualities of physical alterations are derived from the findings of these changes.

NCERT Solutions for Class 7 Science Chapter 6 - List of Topics Covered 

Following is the list of topics covered in Chapter 6 ‘Physical and Chemical Changes’:

• Physical Changes

• Chemical Changes

• Rusting of Iron

• Crystallization

NCERT Solutions for Class 7 Science Chapter 6 - Important Points at a Glance

Check out these important points which should be noted by the students:

• The two types of alterations that might occur are physical and chemical changes.

• Physical alterations are changes in a substance's physical qualities. There are no new compounds formed as a result of these changes. These modifications could be reversible. 

• Chemical reactions result in the creation of new compounds.

• Crystallization can be used to get pure compounds from their solutions.

Introduction to Class 7 Science Chapter 6 – Physical and Chemical Changes 

We notice various changes around us every day, such as the setting of curd from milk, dissolving sugar in water, and many more. These changes can broadly be characterized as chemical and physical changes. In this chapter, we shall learn about various chemical as well as physical changes in detail.

6.1 Physical Changes

Activity 6.1, 6.2, 6.3, 6.4, and 6.5 in this section explain the concept of physical changes. Before starting with the practical experiments, you must know some basic terms and definitions that will help you understand the concept in a better way. 

• Physical Properties: The shape, size, colour, and state of any substance are known as its physical properties.

• Physical Change: When any substance undergoes a change in its physical properties, it is said to undergo a physical change. It is worth noting that a physical change is generally reversible. In a physical change, no new substance is formed. 

Perform all the experiments discussed in this section and you will surely have a better understanding of the physical properties of a substance and physical changes.

6.2 Chemical Changes

Have you ever noticed a film of brownish substance on any iron substance that you left open for some time? This substance is known as rust and the process is known as rusting. Rusting of iron is a chemical change. In this section activities 6.6, 6.7, and 6.8 illustrate the experiments of various chemical changes. You must be thinking, what is a chemical change and how is it different from a physical change?

A change in which one or more new substances are formed is known as a chemical change. A chemical change is commonly termed as a chemical reaction. In the rusting of Iron, we noticed that a new substance that is rust had formed. Similarly, in other experiments discussed in this section, you will notice the formation of one or more chemical substances. Some other examples of chemical change are:

• Ripening of fruits

• Fermentation of grapes

• Digestion of food

• Burning of coal, wood, or leaves. In fact, the burning of a substance is a chemical change because burning is always accompanied by the production of heat and other gases.

In a chemical change, a gas may be formed, a sound might be produced, a new substance may be formed, or heat is produced. A change in smell can also be observed to be a chemical change.

6.3 Rusting of Iron

Rusting of iron is a chemical alteration that not only affects iron articles but slowly and gradually destroys them, as well. In this section, you will study in detail the rusting of iron, its properties, and its cause. Note the following word equation for rusting –

Iron + Oxygen + water → Rust

Note: The presence of oxygen and water is an essential condition for the process of rusting to take place. You can always prevent rusting of iron by preventing the iron article from coming in contact with oxygen, water, or both. 

Another way of preventing rusting is by depositing a layer of metal like chromium or zinc on iron. The process of depositing a layer of zinc on iron is known as galvanization.

6.4 Crystallization

The process of crystallization is a physical change. You must have studied in junior classes that the salt obtained by the evaporation of seawater is not pure. So, the process of forming large crystals of a pure substance is known as crystallization. Activity 6.9 is based on the process of crystallization. It is advised that students must perform this experiment in the science lab under the teacher’s supervision. 

Now, you are well aware of physical and chemical changes. Make a list of some changes happening in your surroundings and try to classify them as physical and chemical changes. This small activity will help you understand the concept in a much better way. In case of any doubts, you can always reach out to the experts at Vedantu on our official website.

NCERT Solutions Class 7 Science Chapters

• Chapter 1 - Nutrition in Plants

• Chapter 2 - Nutrition in Animals

• Chapter 3 - Fibre to Fabric

• Chapter 4 - Heat

• Chapter 5 - Acids

• Chapter 7 - Weather

• Chapter 8 - Winds

• Chapter 9 - Soil

• Chapter 10 - Respiration in Organisms

• Chapter 11 - Transportation in Animals and Plants

• Chapter 12 - Reproduction in Plants

• Chapter 13 - Motion and Time

• Chapter 14 - Electric Current and Its Effects

• Chapter 15 - Light

• Chapter 16 - Water: A Precious Resource

• Chapter 17 - Forests: Our Lifeline

• Chapter 18 - Wastewater Story

Exercise Solutions: 12 Questions (3 short questions and 9 long questions).

Extended Learning: Activities and Projects (4 Questions)

NCERT Solutions for Class 7 Science Chapter 6 - Key Features 

Revising NCERT concepts and exercises is the best way to score good marks in exams. You just need to follow the solution pattern of Vedantu and you can rest assured that you are on the right track. These solutions help you with correct answers as well as serve as a step-by-step NCERT guide for the students having trouble understanding the chapters. Some notable features are:

• You can download the solution PDF at any time at your convenience. 

• All the solutions prepared by Vedantu experts are correct. 

• All important points and step-by-step patterns for answering questions are mentioned here. 

• Work hard and keep revising all the solutions from Vedantu solution PDF.

Benefits of Studying NCERT Solutions for Class 7 Science Chapter 6 

NCERT Solutions for Class 7 Science Chapter 6 Physical and Chemical Changes PDF are now available on the official website of Vedantu. Now, let us see how these NCERT Solutions for Chapter 6 will help the students:

• Students can find all the solutions to their NCERT questions in this PDF. 

• NCERT Solutions will provide you with the most accurate answers, along with a good understanding of the topics. 

• It is important to revise all the NCERT questions and gain an in-depth knowledge of all NCERT Class 7th Science Chapter 6 topics so you score well in exams. 

Hope these NCERT Solutions will help you leverage your Class 7 Science preparation for your exam. Score good marks in Chapter 6 by referring to the NCERT Solutions given in this article and download the free resource right now so that you can study the NCERT notes even when you are offline. 

Do take note of the important points discussed and the list of topics covered in this chapter. A brief on Chapter 6 will help you prepare for the study effectively.