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Class 7 Science question answer: all 12 chapters of Curiosity, with practice

CMDLearn · 4 November 2026

In short: this page lists all 12 chapters of the NCERT Class 7 Science textbook Curiosity (Reprint 2026-27) in the book's order, with the page each chapter starts on and our questions-with-answers guide for it. At the end are 8 quick questions, one idea each from seven chapters, to check yourself before you open a chapter guide.

The questions on this page and in the chapter guides are our own, drafted with AI help. Every answer was checked against the textbook pages named under it, but no practising teacher has reviewed them yet. If you find a mistake, please tell us.

All 12 chapters

The chapter titles and start pages are from the book's contents page (Curiosity, Textbook of Science for Grade 7, Reprint 2026-27).

How to use these guides

1. Do the chapter's activities first. Curiosity teaches through activities; read the chapter and try them, then open our guide.
2. Try each question on paper before you open the answer, and go back to the textbook page named under the answer if you got it wrong.
3. Practise more with the free questions marked in your browser and the printable worksheets linked at the end of this page.

8 quick questions to check yourself

Question 1 (Chapter 3). A torch has fresh cells and its switch is on, but the lamp does not glow. When the lamp is changed for a new one, the torch works. What was wrong with the old lamp?

Answer: the lamp had fused. Its filament was broken, and a broken filament stops the current flowing through the lamp, so it cannot glow even in a complete circuit. (A fused lamp, page 30.)

Question 2 (Chapter 4). A steel plate dropped on the floor rings, but a wooden plank dropped on the same floor makes a dull thud. Which property of metals does this show?

Answer: sonority. Metals make a ringing sound when struck, so they are called sonorous; materials such as wood and coal give only a dull sound. (Sonority, page 46.)

Question 3 (Chapter 7). Why does a quilt stuffed with fluffy cotton keep you warmer on a winter night than a thin cotton sheet?

Answer: the fluffy stuffing holds a lot of trapped air, and air is a poor conductor of heat. The trapped air slows down the flow of heat from your body to the cold air around you, so you stay warm. (Air as a poor conductor, woollen clothes and blankets, page 92.)

Question 4 (Chapter 8). A simple pendulum makes 20 oscillations in 32 seconds. What is its time period?

Answer: 1.6 seconds. The time period is the time for one oscillation, so divide the total time by the number of oscillations: 32 ÷ 20 = 1.6 s. (Time period of a pendulum, page 110.)

Question 5 (Chapter 8). A cyclist rides at a steady 18 km/h. How many metres does she cover in one minute, and what is her speed in m/s?

Answer: 300 metres a minute, which is 5 m/s. 18 km = 18,000 m, covered in 60 minutes, so each minute she covers 18,000 ÷ 60 = 300 m. One minute is 60 seconds, so her speed is 300 ÷ 60 = 5 m/s. (Units of speed, m/s and km/h, page 113.)

Question 6 (Chapter 11). The word TOP is written in capital letters on a card held up in front of a plane mirror. How does it look in the mirror?

Answer: the order of the letters is reversed: left to right you see a back-to-front P, then O, then T. A plane mirror swaps left and right, which is called lateral inversion. T and O look the same when flipped; the P does not, so it shows the change. (Lateral inversion, page 162.)

Question 7 (Chapter 5). Sort these changes into desirable and undesirable: (a) dough rising before it is baked into bread; (b) a cut apple turning brown; (c) bread going mouldy in a cupboard; (d) a seed sprouting in a pot.

Answer: (a) and (d) are desirable; (b) and (c) are undesirable. We want dough to rise and seeds to sprout, but we do not want cut fruit to go brown or stored food to spoil. The same kind of change can be wanted in one place and not in another: food breaking down is a nuisance in the cupboard but useful in a compost pit. (Desirable and undesirable changes, pages 66 and 67.)

Question 8 (Chapter 9). Put these parts of the alimentary canal in the order in which food passes through them: stomach, large intestine, mouth, small intestine, food pipe.

Answer: mouth, food pipe (oesophagus), stomach, small intestine, large intestine. The undigested remains then leave through the anus. (The alimentary canal, Fig. 9.4, page 125.)

Practise more

• Free practice, marked instantly in your browser: practice by chapter, and printable worksheets with answer keys: Class 7 worksheets.
• Class 7 Maths, chapter by chapter, in the same style: start with Large Numbers Around Us.
• In Hindi: Chapter 12, पृथ्वी, चंद्रमा एवं सूर्य, notes and 8 questions with answers.

Where CMDLearn fits

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Sources

All opened and read on 4 November 2026. Page numbers are the printed page numbers of the textbook.

• NCERT, Curiosity, Textbook of Science for Grade 7 (Reprint 2026-27), front matter and contents (chapter titles and start pages): ncert.nic.in/textbook/pdf/gecu1ps.pdf
• NCERT, Curiosity, Chapters 3, 4, 5, 7, 8, 9 and 11, the pages named under each answer above: ncert.nic.in/textbook/pdf/gecu103.pdf, gecu104.pdf, gecu105.pdf, gecu107.pdf, gecu108.pdf, gecu109.pdf and gecu111.pdf at the same address

The chapter titles, page numbers and facts are from the textbook pages above. The questions and answers are our own, and every number was re-checked by script. This guide is general information; follow your teacher and the textbook.

Practise this class: Class 7 worksheets, chapter by chapter · free practice, marked instantly