NCERT Solutions for Class 7th Science Chapter 1 The Ever-Evolving World of Science
Updated on 2026-09-19
About this chapter
Curiosity Grade 7 is not a book of facts to be memorised . It is an invitation to question, to experiment and to explore — science is a process , a way of thinking that welcomes curiosity and is open to the unknown. In Grade 6 we mostly asked what . In Grade 7 we go deeper and ask “How do things work?” , “Why do events happen the way they do?” and “What can we learn from the patterns we see in nature?” The chapter is a guided tour of the whole book — properties of materials and sour fruits, electricity and circuits, metals and non-metals, reversible and irreversible changes, heat, water, life processes in animals and plants, time and speed, light and shadows, and the motions of the Earth and the Moon. Although the book is printed as separate chapters, the different fields of science — phys
- Chapter opening
- Science is a process
- Batteries, lamps and wires; the changes around us
- Life processes in animals and plants; time and speed
- Happy Exploring!
Quick revision
| Term | What it means | Where it comes in the chapter | Everyday example |
|---|---|---|---|
| Science as a process | A way of thinking and working — observing, questioning, testing — not a stock of facts | Page 2 | Testing whether a spoon makes a bulb glow |
| Deeper question | A “how” or “why” question that asks for the mechanism or the cause, not just the name | Page 2 | “Why do events happen the way they do?” |
| Pattern in nature | Something that repeats in a regular way, so it can be predicted and explained | Page 2 | Day and night, the phases of the Moon, the monsoon |
| Property of a material | A feature that helps us tell one material from another and sort them into groups | Pages 2–3 | Sourness of a lemon; a wire that carries current |
| Metals and non-metals | The two big groups materials fall into when we test properties such as conducting electricity | Page 3 | Copper wire (metal) and a plastic scale (non-metal) |
| Reversible change | A change that can be undone, so the original material comes back | Page 3 | Ice melting into water and freezing again |
| Irreversible change | A change that cannot be undone | Page 3 | A torch battery running out; a fruit ripening |
| Life process | A process every living thing must carry out to stay alive | Page 4 | Nutrition, respiration, transport, growth |
| Measuring time | Counting how many times a regularly repeating event has happened | Page 4 | A shadow moving on a sundial; a swinging pendulum |
| Speed | How fast something happens — the distance covered divided by the time taken | Page 4 | 100 m in 20 s = 5 m/s |
| Shadow and eclipse | A shadow forms when an opaque body blocks light; the Earth and the Moon cast shadows too | Page 5 | A solar eclipse; the day–night line on the Earth |
| Question the Answer | The Activity 1.1 game — you are given the answer and you invent the question | Pages 5–6 | Answer: “Just add some milk.” Question: ? |
Exercises
- Chapter opening — In-text Questions Page 1
- Science is a process — In-text Questions Page 2
- Batteries, lamps and wires; the changes around us — In-text Questions Page 3
- Life processes in animals and plants; time and speed — In-text Questions Page 4
- Shadows, eclipses and the movements of the Earth and the Moon — In-text Questions Page 5
- Activity 1.1: Question the Answer — Happy Exploring! Page 5–6