CBSE Class 10 Science Syllabus 2026-27: Marks & Units
CBSE Class 10 Science Syllabus 2026-27: What This Page Confirms
This page sets out the CBSE Class 10 Science syllabus 2026-27 for Subject Code 086, checked against the official CBSE curriculum document on 2026-07-13. The headline fact most students want first: Science carries 80 marks for the theory paper and 20 marks for internal assessment, adding up to 100 (CBSE curriculum document, p. 4).
A second fact worth knowing before you open any chapter: three topics — one each from Chemistry, Biology and Physics — are still part of the syllabus but are marked for formative assessment only, not the year-end paper. That distinction gets its own section below, because it is the point most copy-paste pages get wrong.
Unit-wise Marks Distribution for Class 10 Science 2026-27
| Ch. | Chapter | Study material |
|---|---|---|
| 1 | Chemical Reactions and Equations | Notes · Important Questions · Previous Year Questions |
| 2 | Acids, Bases and Salts | Notes · Important Questions |
| 3 | Metals and Non-metals | Notes |
| 4 | Carbon and its Compounds | Notes |
| 5 | Life Processes | Notes |
| 6 | Control and Coordination | Notes |
| 7 | How do Organisms Reproduce? | Notes |
| 8 | Heredity | Notes |
| 9 | Light – Reflection and Refraction | Notes |
| 10 | The Human Eye and the Colourful World | Notes |
| 11 | Electricity | Notes · Important Questions |
| 12 | Magnetic Effects of Electric Current | Notes |
| 13 | Our Environment | Notes |
The theory exam runs for 3 hours and is worth 80 marks. These are the exact unit-wise figures from the Science_SecP1_2026-27 curriculum document (p. 4) — do not use any table that shows different numbers for this session.
| Unit No. | Unit | Marks |
|---|---|---|
| I | Chemical Substances – Nature and Behaviour | 25 |
| II | World of Living | 25 |
| III | Natural Phenomena | 12 |
| IV | Effects of Current | 13 |
| V | Natural Resources | 05 |
| Total (Theory) | 80 | |
| Internal Assessment | 20 | |
| Grand Total | 100 | |
The curriculum document does not break these marks down further into periods per unit, so treat the marks column above as the only official weightage figure for planning revision time. The official PDF and any sample papers issued alongside it are published on the CBSE Academic curriculum portal, which is the source document behind every figure on this page.
Chapter-wise Study Material for Every Unit
Chapter-wise study material for every unit above:
For a broader view of what else is on the site for this grade, the Class 10 Science study material section links out from each chapter, and the Class 10 study material hub covers every other subject in the same session.
Question Paper Design: Theory Exam Pattern and Competency Weightage
The 80-mark theory paper is built around three competency bands rather than chapter-wise recall. This is how the marks are meant to split, according to the Question Paper Design for Science (086) on page 9 of the curriculum document:
| Competency | Weightage |
|---|---|
| Demonstrate Knowledge and Understanding | 50% |
| Application of Knowledge/Concepts | 30% |
| Formulate, Analyze, Evaluate and Create | 20% |
The paper uses a mix of question types: VSA including objective and Assertion-Reasoning questions, SA, LA, and source-based/case-based/passage-based/integrated questions. An internal choice of approximately 33% is built into the paper, so students always get some flexibility in which questions to attempt (p. 9).
“Competency-based” is not just an exam-paper label. It means only half the marks reward straight recall — the other half asks you to apply a concept to a new situation or analyse data you haven’t seen before. Rote-learning definitions and formulas covers the 50% Knowledge band at best; you still need practice with case-based and application questions to cover the remaining 50%.
Internal Assessment: How the 20 Marks Are Split
The 20 internal assessment marks for Science follow a subject-specific split, not the general Part-1 internal assessment percentages used across other subjects. These are the exact figures from page 9 of the Science curriculum document, and they are what actually appears on the mark sheet:
| Component | Marks |
|---|---|
| Periodic Assessment | 5 + 5 |
| Subject Enrichment (Practical Work) | 5 |
| Portfolio | 5 |
| Total | 20 |
Subject Enrichment (Practical Work) is examined separately by the school, using the experiment list given further down this page. The prescribed reference for how schools should grade this component is the CBSE publication Assessment of Practical Skills in Science – Class X (p. 8), so if your school’s practical marking looks unfamiliar, that is the document to ask your teacher about.
Topics Assessed Only Formatively — Not in the Year-End Exam
This is the section most competitor pages skip, and it is where the common “deleted chapter” confusion starts. The official Note for Teachers on page 6 names exactly three topics that stay in the syllabus but will not be assessed in the year-end examination:
- Periodic Classification of Elements (part of Unit I: Chemical Substances)
- Heredity and Evolution (part of Unit II: World of Living)
- The Motor, Electromagnetic Induction, and Electric Generator portion of Unit IV: Effects of Current
The document’s own wording matters here: these topics are “included in the syllabus but will be assessed only formatively to reinforce understanding without adding to summative assessments” (p. 4–6). Students may be asked to read the topic and prepare a short write-up for their Portfolio, and credit for this can be given under Periodic Assessment or Portfolio marks (p. 6).
Say this plainly, because it is easy to get wrong: the official document does not delete these topics from the syllabus — it removes them only from the year-end examination. Your textbook chapter is unchanged; only the summative exam paper will not carry direct questions from these three portions.
One more detail from the same Note for Teachers: information printed inside boxes across the NCERT textbook is meant for conceptual clarity, but it is not assessed in the year-end examination either (p. 6). Useful to know before you spend revision time memorising box content.
Practical List and Prescribed Books for Class 10 Science
The curriculum document lists 14 experiments, each tagged to the theory unit it supports (p. 7–8). This mapping tells you which practical to revise alongside which chapter:
| Experiment | Unit |
|---|---|
| pH of common samples using pH paper/universal indicator | Unit I |
| Properties of acids and bases with litmus, zinc metal, sodium carbonate | Unit I |
| Classifying reactions: combination, decomposition, displacement, double displacement | Unit I |
| Reactivity of Zn, Fe, Cu, Al with salt solutions | Unit I |
| V–I graph for a resistor; determining resistance | Unit IV |
| Equivalent resistance in series and parallel combinations | Unit IV |
| Temporary mount of a leaf peel to show stomata | Unit II |
| Showing carbon dioxide is released during respiration | Unit II |
| Properties of acetic acid (odour, solubility, litmus, reaction with sodium hydrogen carbonate) | Unit I |
| Cleaning capacity of soap in soft and hard water | Unit I |
| Focal length of a concave mirror and a convex lens | Unit III |
| Tracing a ray through a rectangular glass slab | Unit III |
| Binary fission in Amoeba and budding in yeast/Hydra (slides) | Unit II |
| Tracing the path of light through a glass prism | Unit III |
| Identifying parts of a dicot seed embryo (pea, gram, red kidney bean) | Unit II |
Notice that Unit V (Natural Resources) has no listed experiment, and Unit I contributes the largest share of practicals — worth keeping in mind when you plan lab-record revision time.
The prescribed books for this syllabus, as listed on page 8 of the curriculum document, are:
- Science – Textbook for Class X, NCERT Publication
- Assessment of Practical Skills in Science – Class X, CBSE Publication
- Laboratory Manual – Science – Class X, NCERT Publication
- Exemplar Problems Class X, NCERT Publication
- Reading Material – Science – Class X (2026-27), CBSE
You can browse the official NCERT textbook portal for the prescribed Class X Science book itself, alongside the CBSE-published practical skills manual noted above.
Common mistakes students make with this syllabus
| Mistake | Correct rule | How to check your answer |
|---|---|---|
| Assuming Heredity and Evolution is deleted from the textbook | It remains in the syllabus; only removed from the year-end summative paper | Re-read the Note for Teachers, p. 6 — it says “assessed only formatively,” not “deleted” |
| Using the generic Part-1 internal assessment percentages for Science | Science internal assessment follows its own 5+5+5+5 split on p. 9 | Match your school’s IA sheet against Periodic Assessment (10), Subject Enrichment (5), Portfolio (5) |
| Spending revision time on boxed information in the NCERT textbook | Box content is in the syllabus but not assessed in the year-end exam | Cross-check the topic against Note for Teachers point 3, p. 6 |
| Expecting a paper with no choice of questions | Approximately 33% internal choice is built into the theory paper | Count the either-or/optional questions in any official sample paper against the p. 9 figure |
Frequently Asked Questions About the Class 10 Science Syllabus 2026-27
Is Heredity and Evolution removed from the CBSE Class 10 Science syllabus 2026-27?
No. Heredity and Evolution stays in the syllabus. The curriculum document only removes it from the year-end summative exam — it will be assessed formatively through Portfolio or Periodic Assessment (p. 6).
How many marks does the Effects of Current unit carry in Class 10 Science 2026-27?
Unit IV, Effects of Current, carries 13 marks out of the 80-mark theory paper (p. 4).
What is the CBSE subject code for Class 10 Science?
The subject code is 086 (p. 1).
Does the Class 10 Science internal assessment include a separate practical exam mark?
Yes. Subject Enrichment (Practical Work) carries 5 marks within the 20-mark internal assessment, examined by the school using the prescribed experiment list and the CBSE publication Assessment of Practical Skills in Science – Class X (p. 8–9).
How much internal choice is given in the Class 10 Science theory paper?
Approximately 33% internal choice is provided across the 80-mark theory paper (p. 9).
Which Class 10 Science topics are assessed only through formative assessment and not the year-end exam?
Periodic Classification of Elements (Unit I), Heredity and Evolution (Unit II), and the motor/electromagnetic induction/electric generator portion of Effects of Current (Unit IV) — named in the Note for Teachers on page 6.
For quick access to more study resources across grades, you can also start from the site’s main CBSE study material section.
Reference: CBSE Class 10 Science curriculum document, session as stated on cbseacademic.nic.in.