Tamil Nadu SSLC Science Chapter Wise Notes 2027 - Samacheer Kalvi All Chapters

In short: Tamil Nadu SSLC Science 2027 follows the Samacheer Kalvi textbook with 21 chapters — DIFFERENT from NCERT. The 100-mark pure theory paper covers Physics (Laws of Motion — Newton's laws/gravitation, Optics — reflection/refraction/lenses, Thermal Physics — heat/calorimetry, Electricity — Ohm's law/circuits/power, Acoustics — sound waves/echo, Nuclear Physics — radioactivity/fission/fusion), Chemistry (Atoms and Molecules — mole concept/stoichiometry, Periodic Classification — modern table/trends, Chemical Bonding — ionic/covalent/metallic, Solutions — types/concentration/colligative, Chemical Reactions — types/balancing/redox, Carbon and Its Compounds — organic chemistry/polymers), and Biology (Plant Anatomy and Physiology — tissues/photosynthesis, Transportation in Plants and Circulation in Animals — xylem/phloem/heart, Nervous System — brain/reflex arc/sense organs, Reproduction in Plants and Animals — sexual/asexual/human, Heredity and Evolution — Mendel/DNA/natural selection, Plant and Animal Breeding — hybridisation/cattle/poultry, Health and Diseases — infectious/deficiency/prevention, Environmental Management — ecosystem/pollution/conservation). Book-back questions account for 60-70% of the exam.

Tamil Nadu Science Is Not NCERT — Know the Difference

Tamil Nadu SSLC Science follows the Samacheer Kalvi textbook, which is fundamentally different from the NCERT textbook used by CBSE, UP Board, Karnataka, and Rajasthan. The chapters are organised differently, topics are covered at different depths, and the exam is a 100-mark pure theory paper with no separate practical component — practicals are integrated into the written exam through application-based questions.

The single most important exam strategy for TN SSLC Science: book-back questions account for 60-70% of the paper. If you master every question at the end of each chapter in the Samacheer Kalvi textbook, you are already prepared for the majority of the exam. For chapter-wise weightage details, see the TN SSLC Science marks weightage guide.

Complete Chapter List

Physics (Chapters 1-6)

Chemistry (Chapters 7-12)

Biology (Chapters 13-21)

Chapter-Wise Notes

Chapter 1: Laws of Motion

• Core concepts: Newton's First Law (inertia), Second Law (F = ma), Third Law (action-reaction). Universal Law of Gravitation: F = Gm₁m₂/r². Acceleration due to gravity (g = 9.8 m/s²), g = GM/R². Free fall. Mass vs weight. Weight on moon (1/6th of earth).
• Key formulas: F = ma, W = mg, F = Gm₁m₂/r², g = GM/R². Equations of motion: v = u + at, s = ut + ½at², v² = u² + 2as.
• Book-back focus: Numerical problems on F = ma, gravitational force, and equations of motion are frequently from book-back exercises.
• Exam tip: Expect 2-3 numericals (4-6 marks). Practice equations of motion and gravitational force calculations. The difference between mass and weight is a popular 2-mark question.

Chapter 2: Optics

• Core concepts: Laws of reflection. Spherical mirrors — concave and convex, ray diagrams, mirror formula (1/f = 1/v + 1/u), magnification. Refraction — Snell's law, refractive index. Total internal reflection. Lenses — convex and concave, lens formula (1/f = 1/v - 1/u), power of lens. Human eye — accommodation, defects (myopia, hypermetropia), corrections. Dispersion and scattering.
• Key formulas: 1/f = 1/v + 1/u (mirror), 1/f = 1/v - 1/u (lens), P = 1/f, n = sin i/sin r.
• Must-know diagrams: Ray diagrams (all positions for mirrors and lenses), eye defects and corrections, prism dispersion.
• Exam tip: Highest-marks Physics chapter. Expect 2-3 numericals and 1-2 diagram questions (7-9 marks total). Master all ray diagram rules. Book-back numerical problems are very likely to repeat. For study techniques, see the science study guide.

Chapter 3: Thermal Physics

• Core concepts: Heat vs temperature. Scales — Celsius, Fahrenheit, Kelvin. Specific heat capacity: Q = mcΔT. Calorimetry: heat lost = heat gained. Latent heat: Q = mL. Gas laws — Boyle's, Charles', combined gas equation.
• TN-specific: Tamil Nadu covers gas laws at Class 10, unlike NCERT where this comes in Class 11.
• Exam tip: Calorimetry numericals (3-4 marks) and gas law problems are common. Convert all temperatures to Kelvin for gas law calculations.

Chapter 4: Electricity

• Core concepts: Electric current, potential difference. Ohm's law: V = IR. Resistance: R = ρl/A. Series and parallel combinations. Heating effect: H = I²Rt. Power: P = VI. Energy: E = Pt. Household wiring — fuse, earthing, three-pin plug.
• Key formulas: V = IR, P = VI = I²R = V²/R, E = Pt, R(series) = R₁+R₂, 1/R(parallel) = 1/R₁+1/R₂.
• Exam tip: Second-highest marks Physics chapter. Expect 2-3 numericals. Series-parallel equivalent resistance, power, and energy calculations are staple questions. Circuit diagrams should be drawn neatly with proper symbols. Use the answer writing strategy for presentation.

Chapter 5: Acoustics

• Core concepts: Sound waves — longitudinal, characteristics (frequency, amplitude, wavelength, velocity). Speed of sound in different media. Echo — minimum distance (17.2 m), reverberation. Resonance. Applications — sonar, ultrasound in medicine. Human ear structure.
• TN-specific: Acoustics is a dedicated chapter in Samacheer Kalvi but not a separate chapter in NCERT Class 10.
• Exam tip: Speed of sound calculations, echo distance problems, and characteristics of sound are common 2-3 mark questions. Know the formula: v = fλ and echo distance calculation.

Chapter 6: Nuclear Physics

• Core concepts: Atomic nucleus — protons, neutrons. Isotopes, isobars, isotones. Radioactivity — α, β, γ rays and their properties. Nuclear fission (chain reaction, nuclear reactor, atomic bomb) and fusion (hydrogen bomb, stellar energy). Half-life. Uses and hazards of radioactivity. Radiation safety.
• TN-specific: Nuclear Physics is a full chapter in Samacheer Kalvi, giving it more depth than NCERT at this level.
• Exam tip: α vs β vs γ comparison table is a common question. Nuclear fission vs fusion comparison carries 3-4 marks. Know at least 4 applications of radioactivity.

Chapter 7: Atoms and Molecules

• Core concepts: Dalton's atomic theory. Atomic mass, molecular mass. Mole concept — 1 mole = 6.022 × 10²³ (Avogadro's number). Molar mass calculations. Percentage composition. Stoichiometry — balanced equation-based calculations.
• Key formulas: n = m/M = V/22.4 (at STP) = N/Nₐ. Percentage composition = (mass of element / molar mass) × 100.
• Exam tip: Mole concept numericals carry 3-5 marks. Show all steps: balanced equation → mole ratios → calculations. Practice at least 20 stoichiometry problems from the book-back exercises.

Chapter 8: Periodic Classification of Elements

• Core concepts: Historical development — Döbereiner, Newlands, Mendeleev. Modern periodic table — atomic number basis. Periods and groups. Electronic configuration and position. Trends across periods and down groups.
• Exam tip: Standard trend questions carry 2-3 marks. Know 3+ limitations of Mendeleev's table.

Chapter 9: Chemical Bonding

• Core concepts: Octet rule. Ionic bonding — electron transfer, formation of NaCl, MgO. Properties of ionic compounds. Covalent bonding — electron sharing, single/double/triple bonds, H₂O, CO₂, N₂. Properties of covalent compounds. Metallic bonding — electron sea model. Electron dot structures (Lewis structures).
• TN-specific: Metallic bonding is covered here, unlike NCERT where it comes in Class 11.
• Exam tip: Lewis structure drawing carries 2-3 marks. Ionic vs covalent comparison is a popular question. Practice electron dot structures for at least 15 compounds from the textbook. For TN SSLC important questions, see our detailed guide.

Chapter 10: Solutions

• Core concepts: Types of solutions (solid, liquid, gas). Solubility and factors affecting it. Concentration — mass percentage, molarity, molality. Saturated, unsaturated, supersaturated solutions. Colligative properties (basic concept). Henry's law (basic).
• TN-specific: Solutions as a dedicated chapter is unique to Samacheer Kalvi — NCERT covers this at Class 12 level.
• Exam tip: Concentration calculation problems carry 3-4 marks. Practice molarity and mass percentage calculations. Book-back problems on this chapter are frequently repeated.

Chapter 11: Chemical Reactions

• Core concepts: Types — combination, decomposition, displacement, double displacement, redox. Balancing equations. Factors affecting rate of reaction (temperature, concentration, catalyst, surface area). Oxidation-reduction in terms of electron transfer.
• Exam tip: Balancing equations and identifying reaction types are basic skills worth 3-5 marks. Practice 20+ balanced equations.

Chapter 12: Carbon and Its Compounds

• Core concepts: Carbon — tetravalency, catenation. Hydrocarbons — alkanes, alkenes, alkynes. Functional groups. IUPAC nomenclature. Chemical properties. Polymers — natural and synthetic. Soaps and detergents.
• Exam tip: IUPAC naming carries 2-3 marks. Polymer classification is a common short-answer question. Practice naming 15+ compounds.

Chapters 13-14: Plant Anatomy and Transportation

• Core concepts: Plant tissues — meristematic and permanent. Photosynthesis — light and dark reactions. Transpiration. Xylem and phloem transport. Human circulatory system — heart structure, blood composition, double circulation. Blood groups.
• Must-know diagrams: Plant/animal tissues, heart cross-section, xylem/phloem.
• Exam tip: Diagram questions carry 3-5 marks. Practice heart diagram with blood flow arrows. Enzyme table for digestion is common.

Chapter 15: Nervous System

• Core concepts: Central and peripheral nervous system. Brain parts — cerebrum, cerebellum, medulla. Spinal cord. Neuron structure. Reflex arc. Sense organs. Endocrine glands and hormones.
• Must-know diagrams: Brain (labelled), neuron, reflex arc.
• Exam tip: Reflex arc diagram is guaranteed. Brain functions table carries 3 marks. Hormone table (gland → hormone → function) is popular. Follow the TN SSLC last 45 days strategy for revision.

Chapters 16-17: Reproduction, Heredity and Evolution

• Core concepts: Asexual reproduction methods. Sexual reproduction in plants (flower structure, pollination, fertilization). Human reproductive system. Mendel's experiments — monohybrid and dihybrid crosses. DNA structure. Sex determination. Natural selection and speciation.
• Must-know diagrams: Reproductive systems, flower L.S., monohybrid cross, sex determination.
• Exam tip: Mendel's cross is a guaranteed 4-5 mark question. Reproductive system diagrams carry 3-5 marks. These are high-value, frequently tested topics.

Chapters 18-20: Breeding, Health, Environment

• Core concepts: Hybridisation techniques in plants and animals. Cattle and poultry breeding. Infectious diseases — bacterial, viral, fungal, protozoan. Deficiency diseases. Immunity types. Ecosystem components. Food chains. Pollution. Conservation. Biodiversity.
• Exam tip: Disease table (disease, pathogen, symptoms, prevention) is a popular 3-4 mark answer. Ecosystem food chain with energy flow is common. These chapters have straightforward questions ideal for scoring. See the TN SSLC chapter-wise weightage for detailed breakdown.

How to Use These Notes

1. Master the Samacheer Kalvi textbook: This is non-negotiable. 60-70% of exam questions come from book-back exercises. Solve every single book-back question at least twice.

2. Focus on TN-specific chapters: Acoustics, Nuclear Physics, Solutions, and Animal Breeding are unique to the Tamil Nadu syllabus. Give extra attention to these as NCERT-based resources won't help here.

3. Practice book-back questions religiously: After reading a chapter, immediately solve all book-back questions (Choose the correct answer, Fill in the blanks, Match the following, Short Answers, Long Answers). These are your exam questions.

4. Diagram practice: Science has extensive diagram requirements. Draw at least 2 diagrams daily. Key diagrams: heart, brain, reflex arc, nephron, eye, ray diagrams, circuit diagrams, flower L.S.

5. Numerical problem practice: Physics chapters (Motion, Optics, Electricity, Thermal) and Chemistry chapters (Mole concept, Solutions) require numerical practice. Solve 150+ problems across all chapters.

6. Create subject-wise revision sheets: One for Physics formulas, one for Chemistry equations, one for Biology diagrams. Revise daily during the final month.

7. Solve previous year papers: TN SSLC repeats book-back questions frequently. Solving 5+ previous year papers will show you the repetition pattern. Use the board exam time management guide for paper-solving practice.

Priority Chapters by Weightage

Frequently Asked Questions

Is TN SSLC Science different from CBSE?

Yes, fundamentally different. Tamil Nadu follows the Samacheer Kalvi textbook with 21 chapters, while CBSE follows NCERT with 16 chapters. TN includes unique chapters like Acoustics, Nuclear Physics, Solutions, and Animal Breeding that NCERT does not cover at Class 10. The exam is also 100 marks pure theory with no separate practical marks.

How many chapters are in TN SSLC Science?

There are 21 chapters divided across Physics (6 chapters), Chemistry (6 chapters), and Biology (9 chapters). This is more extensive than NCERT's 16 chapters and includes topics that NCERT covers only at Class 11-12 level.

What percentage of questions come from book-back?

Approximately 60-70% of the TN SSLC Science paper consists of questions directly from or closely based on the book-back exercises in the Samacheer Kalvi textbook. This makes the textbook your most important preparation resource.

Which are the highest-scoring chapters?

Optics (7-9 marks), Electricity (7-9 marks), Laws of Motion (6-8 marks), and Heredity and Evolution (5-6 marks) are the highest-scoring chapters. Physics overall contributes approximately 35-40 marks out of 100.

How should I handle TN-specific topics not in NCERT?

For chapters like Acoustics (Ch 5), Nuclear Physics (Ch 6), Solutions (Ch 10), and Animal Breeding (Ch 18), rely entirely on the Samacheer Kalvi textbook. Online NCERT resources won't cover these. Focus on book-back questions and textbook examples for these chapters.

Can I score 90+ in TN SSLC Science?

Yes, scoring 90+ is achievable because of the book-back question pattern. If you master all book-back questions (which are 60-70% of the paper), you already have 60-70 marks secured. Add thorough understanding of concepts, diagram practice, and numerical problem-solving, and 90+ is realistic with disciplined preparation.

Related Guides

• Tamil Nadu SSLC Science Chapter-Wise Marks Weightage 2027
• Tamil Nadu SSLC Important Questions 2027 — All Subjects
• Tamil Nadu SSLC Model Paper 2027 — All Subjects with Answer Key
• Tamil Nadu SSLC Last 45 Days Subject-Wise Strategy
• Tamil Nadu SSLC Chapter-Wise Weightage 2027
• How to Study Science Effectively for Board Exams

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