CBSE · Class 10 Science
CBSE Class 10 Science syllabus — all 13 chapters, sorted
Class 10 Science is thirteen chapters in one book and one 80-mark paper covering Physics, Chemistry and Biology together, with 20 further marks from internal assessment and practicals. Below is every chapter, labelled by stream, so you can see how the year is actually balanced.
- Chapters
- 13
- Paper
- 80 marks
- Internal
- 20 marks
- Streams
- 3 in one paper
How the 100 marks divide
| Section | Marks | Share |
|---|---|---|
| Written theory paper Physics, Chemistry and Biology in one paper | 80 | |
| Internal assessment practicals and school assessment | 20 | |
| Total | 100 |
The 80-mark paper, unit by unit
This is the table most students never see, because CBSE publishes it inside the curriculum PDF rather than on the syllabus pages that rank. Half the paper sits in the first eight chapters.
| Section | Marks | Share |
|---|---|---|
| Unit I — Chemical Substances: Nature and Behaviour Chapters 1 to 4 | 25 | |
| Unit II — World of Living Chapters 5 to 8 | 25 | |
| Unit III — Natural Phenomena Chapters 9 and 10 | 12 | |
| Unit IV — Effects of Current Chapters 11 and 12 | 13 | |
| Unit V — Natural Resources Chapter 13 | 5 | |
| Total | 80 |
CBSE lists topics under each unit, not chapter numbers. The chapter ranges above are our mapping of those topic lists onto the NCERT chapter order, so you can use the weighting while revising chapter by chapter.
Where the other 20 marks come from
| Section | Marks | Share |
|---|---|---|
| Periodic assessment | 5 | |
| Multiple assessment | 5 | |
| Portfolio | 5 | |
| Subject enrichment — practical work 14 listed practicals | 5 | |
| Total | 20 |
Not in this year’s paper
“The topics Periodic Classification of Elements; Heredity and Evolution; and Electric Effects of Electric Current will not be assessed in the year-end examination.”
Read the wording before you act on it. Those are CBSE’s topic names and they do not map one-to-one onto the chapter titles in the current NCERT book: Periodic Classification of Elements is not a separate chapter any more, and the chapter now called simply “Heredity” no longer carries the Evolution material. It is topic-level guidance, not a licence to skip chapters 8 or 12 — check with your school, and check the PDF linked at the foot of this page rather than a summary of it.
The three streams, side by side
Seeing the split matters because students plan as though the book were in three blocks. It is not — the chapters alternate, so your revision has to.
Physics
4- 9. Light — Reflection and Refraction
- 10. The Human Eye and the Colourful World
- 11. Electricity
- 12. Magnetic Effects of Electric Current
Chemistry
4- 1. Chemical Reactions and Equations
- 2. Acids, Bases and Salts
- 3. Metals and Non-metals
- 4. Carbon and its Compounds
Biology
5- 5. Life Processes
- 6. Control and Coordination
- 7. How do Organisms Reproduce?
- 8. Heredity
- 13. Our Environment
Every chapter, in book order
Science
13 chaptersNCERT Science
One 80-mark paper covering Physics, Chemistry and Biology together, plus 20 marks of practical work.
- 1 Chemical Reactions and Equations Chemistry
- 2 Acids, Bases and Salts Chemistry
- 3 Metals and Non-metals Chemistry
- 4 Carbon and its Compounds Chemistry
- 5 Life Processes Biology
- 6 Control and Coordination Biology
- 7 How do Organisms Reproduce? Biology
- 8 Heredity Biology
- 9 Light — Reflection and Refraction Physics
- 10 The Human Eye and the Colourful World Physics
- 11 Electricity Physics
- 12 Magnetic Effects of Electric Current Physics
- 13 Our Environment Biology
Class 10 Science syllabus — common questions
- How many chapters are in CBSE Class 10 Science?
- Thirteen, covering Physics, Chemistry and Biology in a single book and a single 80-mark paper. Four are Chemistry, five are Biology and four are Physics.
- Which Class 10 Science chapters are Physics?
- Light — Reflection and Refraction, The Human Eye and the Colourful World, Electricity, and Magnetic Effects of Electric Current. Electricity is where most numerical marks live.
- Is Class 10 Science one paper or three?
- One. All three streams are examined together in a single 80-mark paper, plus 20 marks of internal assessment including practical work. That is why leaving one stream until the end is risky — you cannot trade a bad Biology section against a good Physics one on separate papers.
- Which Science chapters carry the most marks?
- CBSE publishes the weighting by unit, not by chapter. For 2026-27 it is Chemical Substances 25, World of Living 25, Effects of Current 13, Natural Phenomena 12 and Natural Resources 5, out of 80. In chapter terms that puts half the paper in chapters 1 to 8, which is why leaving the Chemistry and Biology blocks late costs more than it looks.
- Is anything left out of the Class 10 Science paper this year?
- Yes. CBSE states that Periodic Classification of Elements, Heredity and Evolution, and Electric Effects of Electric Current will not be assessed in the year-end examination for 2026-27. Read that carefully: those are CBSE’s topic names, and they do not line up one-to-one with the NCERT chapter titles — Periodic Classification is not a separate chapter in the current book, and the chapter called Heredity no longer carries the Evolution material. Treat it as topic-level guidance and confirm with your school before dropping anything.
- How are the 20 internal marks earned in Science?
- Five marks each for periodic assessment, multiple assessment, portfolio and subject enrichment. Subject enrichment is the practical work — the curriculum lists 14 practicals for Class 10 Science.