NCERT Exemplar Solution for Class 7 Science Chapter-6 Physical and Chemical Changes
Changes take place around us every day, from melting ice and boiling water to burning paper and rusting iron. Chapter 6 Physical and Chemical Changes helps students understand how substances change in different situations and how these changes affect their properties. The chapter explains the difference between temporary and permanent changes using simple activities and real-life examples. Students learn how some changes can be reversed while others create entirely new substances. The NCERT Exemplar Solution for Class 7 Science provides detailed explanations that make these scientific concepts easier to understand and apply. By practising the NCERT Exemplar Solution for class 7, students improve their reasoning ability and gain confidence in answering conceptual questions. These solutions also support classroom learning and strengthen the concepts included in NCERT solutions for class 7 science.
Find the Exercises PDF of NCERT Exemplar Solution for Class 7 Science Chapter-6 Physical and Chemical Changes
Understanding Physical Changes
A physical change is a change in which the substance changes only in shape, size, or state, but no new substance is formed. These changes are usually temporary and can often be reversed. The chapter explains physical changes through common examples such as melting ice, folding paper, breaking glass, and dissolving sugar in water.
When ice melts into water, only the state changes from solid to liquid. The substance remains water, and the process can be reversed by freezing it again. Similarly, stretching a rubber band changes its shape but not its composition. These examples help students identify the characteristics of physical changes in everyday life. The chapter also teaches that physical changes may involve energy changes, but the original substance still remains the same. Students learn to observe carefully and differentiate between physical and chemical changes based on their properties. The NCERT Exemplar Solution for Class 7 includes practical questions and activities that help students understand these concepts more effectively. By solving exemplar exercises, learners improve their observation skills and scientific thinking abilities.
Chemical Changes and Their Characteristics
Chemical changes are different because they result in the formation of new substances with new properties. These changes are usually permanent and cannot be reversed easily. The chapter explains chemical changes through activities such as burning paper, curd formation, rusting of iron, and cooking food.
When paper burns, ash and smoke are formed, and the original paper cannot be obtained again. Rusting is another important example discussed in this chapter. Iron reacts with oxygen and moisture in the air to form rust, which weakens the metal over time. Students also learn that chemical changes often produce heat, light, sound, or gas. Some chemical reactions may involve colour changes or the formation of precipitates. These observations help students identify whether a change is physical or chemical. The chapter explains how rusting can be prevented through painting, oiling, greasing, or galvanisation. These methods protect iron objects from coming in contact with air and moisture. Such practical examples make science more meaningful and relatable.
The NCERT Exemplar Solution provides clear answers to textbook and competency-based questions, helping students understand difficult concepts step by step. Regular practice improves confidence and strengthens exam preparation.
Difference Between Physical and Chemical Changes
One of the most important learning outcomes of this chapter is understanding the difference between physical and chemical changes. Physical changes affect only the appearance or state of a substance, while chemical changes produce entirely new substances. For example, cutting wood into pieces is a physical change because the wood remains the same substance. However, burning wood is a chemical change because ash, gases, and heat are produced. Similarly, dissolving salt in water is physical, while curd formation from milk is chemical.
The chapter encourages students to analyse changes carefully before classifying them. This improves logical thinking and scientific reasoning. The activities and examples included in the chapter make learning interactive and enjoyable. The NCERT Exemplar Solution for Class 7 helps students revise these differences through multiple-choice questions, fill-in-the-blanks, and reasoning-based exercises. These questions are highly useful for school exams and help students improve their conceptual understanding.
Importance of Practising NCERT Exemplar Questions
NCERT exemplar questions are designed to test a student’s understanding rather than simple memorisation. They help learners apply scientific concepts in practical situations and develop analytical skills. Chapter 6 contains many observation-based questions that improve critical thinking abilities. Practising the NCERT Exemplar Solution regularly helps students identify common mistakes and understand the logic behind scientific phenomena. It also improves answer-writing skills and builds confidence for exams.
This chapter forms a foundation for advanced chemistry topics in higher classes. Understanding physical and chemical changes at an early stage makes future science learning easier and more interesting. Consistent practice allows students to strengthen their concepts and perform better academically.