Class 7 Science Chapter 1 NCERT Solutions: The Ever-Evolving World of Science

Question 1.
How do things work? (Page 2)

Answer:

Everything functions through the interaction of different parts or materials. For instance, the movement of gears in a clock helps measure time, plant roots take in water to support growth, and an electric bulb glows when current flows through it. In the same way, the human body operates as a system where each organ performs a specific function to maintain health. Science allows us to understand how these parts coordinate with one another to make systems work smoothly.

Question 2.

Why do events happen the way they do? (Page 2)

Answer: Events occur as a result of cause and effect, where every action leads to a specific outcome. For example, rainfall makes the ground wet because the rain causes that change. In nature and everyday life, happenings follow certain conditions, patterns, and rules. Science helps us recognize these patterns, allowing us to explain and predict why events take place in a particular way.

Question 3.

What can we learn from the patterns that we see in nature? (Page 2)

Answer: By observing patterns in nature, we gain insight into how systems function, how changes take place, and how future events can be anticipated. For instance, the cycle of seasons occurs in a predictable order, allowing us to know when to expect spring, summer, autumn, or winter. Similarly, the growth of plants and the behaviour of animals follow regular patterns that explain their life cycles. Understanding these patterns helps us make informed choices and see the world more clearly.

Question 4.

Why are some fruits sour? (Page 2)

Answer: Some fruits taste sour because they contain natural acids such as citric acid. The level of acidity and the stage of ripeness influence how sour a fruit tastes. For example, lemons have a sharp sour taste due to their high citric acid content, while fruits like green mangoes gradually become sweeter as they ripen.

Question 5.

What happens when we wash the haldi stain on our uniform? (Page 2)

Answer: When a turmeric (haldi) stain on a uniform is washed with soap, the basic nature of the soap reacts with the stain. Due to this reaction, the stain turns red in colour, which makes it more difficult to remove.

Activities 1.1 Question the Answer (Pages 5-6)

Question 1.
What should I do if my coffee is too strong?

Answer:

Simply add a little milk.

Question 2.

Why did my cat have trouble chewing its food?

Answer: Since the cat’s teeth were not straight.

Note: Students may frame additional questions on their own.

Question 3.

What should I do? I forgot to bring your bathrobe.

Answer: No need to worry, I have my towel.

Question 4.

If a box contains 6 sets of books, and each set has 7 books, how many books are in the box?

Answer:

42

Explore the Exciting World of Science in Class 7

Begin your journey into Class 7 Science Chapter 1: The Ever-Evolving World of Science and discover how curiosity fuels discovery. This chapter encourages you to ask questions, perform fun experiments, and develop a deeper understanding of the world around you.

By exploring key topics—from properties of materials to the wonders of nature—you'll learn the importance of exploration and curiosity in science. Regular reading and observation will help reinforce your knowledge for school exams and beyond.

Mastering this chapter with NCERT Solutions for 2025-26 helps you develop scientific thinking skills. Focus on activity-based questions, review concepts, and always keep your curiosity alive for the best exam success!