CBSE Class 10 Science chapter-wise weightage 2027
How the board shares out the 80 theory marks of the 2027 Class 10 Science exam, unit by unit, with the chapters in each unit. From CBSE's 2026-27 curriculum, checked on 2026-11-10.
| Unit | Chapters | Marks | Share |
|---|---|---|---|
| Chemical Substances: Nature and Behaviour | 1. Chemical Reactions and Equations 2. Acids, Bases and Salts 3. Metals and Non-metals 4. Carbon and its Compounds | 25 | 31% |
| World of Living | 5. Life Processes 6. Control and Coordination 7. How do Organisms Reproduce? 8. Heredity | 25 | 31% |
| Natural Phenomena | 9. Light: Reflection and Refraction 10. The Human Eye and the Colourful World | 12 | 15% |
| Effects of Current | 11. Electricity 12. Magnetic Effects of Electric Current | 13 | 16% |
| Natural Resources | 13. Our Environment | 5 | 6% |
| Total | 80 | 100% |
Plus 20 marks for internal assessment. Where a unit has more than one chapter, the board gives marks to the unit, not to each chapter.
Where the marks are
The paper: 39 questions, 80 marks, 3 hours
| Section | Questions | How many | Marks each | Total |
|---|---|---|---|---|
| Section A | Multiple-choice and assertion-reason | 20 | 1 | 20 |
| Section B | Very short answer | 6 | 2 | 12 |
| Section C | Short answer | 7 | 3 | 21 |
| Section D | Long answer | 3 | 5 | 15 |
| Section E | Case-based | 3 | 4 | 12 |
From CBSE's 2026-27 sample question paper. Internal choice is given in some questions.
How to use this
- Start with Chemical Substances: Nature and Behaviour and World of Living: together they are 50 of the 80 marks.
- Do not skip a small unit: Natural Resources is 5 marks, often in short questions you can be sure of.
- Find your weakest chapter first: a free 20-minute test names it, then practise it on its page.
Practise the whole paper: free Class 10 Science sample papers, set to these weights.
Questions students ask
Chemical Substances: Nature and Behaviour: 25 marks; World of Living: 25 marks; Natural Phenomena: 12 marks; Effects of Current: 13 marks; Natural Resources: 5 marks. Total 80 marks in the theory paper, plus 20 for internal assessment.
Chemical Substances: Nature and Behaviour, with 25 of 80 marks, then World of Living with 25.
No. The unit marks in CBSE's 2026-27 curriculum are the same as in 2025-26.
39 questions for 80 marks in 3 hours: Section A, 20 × 1 mark (multiple-choice and assertion-reason); Section B, 6 × 2 marks (very short answer); Section C, 7 × 3 marks (short answer); Section D, 3 × 5 marks (long answer); Section E, 3 × 4 marks (case-based).
Source: CBSE curriculum 2026-27, Science. Unit marks from CBSE's 2026-27 curriculum; question pattern from CBSE's 2026-27 sample question papers. Read on cbseacademic.nic.in on 2026-11-10. Unit marks are unchanged from 2025-26.