Class 10 Science Formulas Handbook (Chapter-wise)

Every key reaction, rule and result from the Class 10 Science NCERT syllabus, organised by chapter, in one place. Covering all 13 chapters of the current 2026-27 NCERT Class 10 Science textbook, each cross-linked to our full Chapter-wise Solutions.

Class 10 Science Key Reactions & Formulas Handbook

Chapter 1: Chemical Reactions and Equations

• Balancing rule: number of atoms of each element must be equal on both sides of the equation (law of conservation of mass)
• Combination reaction: A + B → AB (e.g. CaO + H₂O → Ca(OH)₂)
• Decomposition reaction: AB → A + B, may need heat (thermal), light (photolytic) or electricity (electrolytic) — e.g. 2FeSO₄ → Fe₂O₃ + SO₂ + SO₃ (thermal)
• Displacement reaction: A + BC → AC + B (a more reactive element displaces a less reactive one, e.g. Fe + CuSO₄ → FeSO₄ + Cu)
• Double displacement reaction: AB + CD → AD + CB, often forms a precipitate (e.g. Na₂SO₄ + BaCl₂ → BaSO₄↓ + 2NaCl)
• Oxidation: gain of oxygen / loss of hydrogen; Reduction: loss of oxygen / gain of hydrogen (both happen together in a redox reaction)
• Corrosion: slow attack of metal surface by air/moisture/chemicals (e.g. rusting of iron); Rancidity: oxidation of fats/oils in food causing bad smell/taste

Chapter 2: Acids, Bases and Salts

• Acid + Metal → Salt + H₂↑ (e.g. Zn + H₂SO₄ → ZnSO₄ + H₂)
• Metal carbonate/bicarbonate + Acid → Salt + CO₂↑ + H₂O
• Acid + Base → Salt + Water (neutralisation); ionic form: H⁺ + OH⁻ → H₂O
• Metallic oxide + Acid → Salt + Water  |  Non-metallic oxide + Base → Salt + Water
• pH scale: 0–14; <7 acidic, =7 neutral, >7 basic
• Chlor-alkali process (making NaOH): 2NaCl + 2H₂O → (electrolysis) → 2NaOH + Cl₂↑ + H₂↑
• Bleaching powder: Ca(OH)₂ + Cl₂ → CaOCl₂ + H₂O
• Plaster of Paris: CaSO₄·2H₂O (gypsum) heated at ~373K → CaSO₄·½H₂O + 1½H₂O
• Common salt formulas: washing soda Na₂CO₃·10H₂O, baking soda NaHCO₃, blue vitriol CuSO₄·5H₂O

More chapters (Metals and Non-metals, Carbon and its Compounds, and beyond) will be appended here as their Solutions are published.

Chapter 3: Metals and Non-metals

• Reactivity series (high to low): K > Na > Ca > Mg > Al > Zn > Fe > Pb > H > Cu > Ag > Au
• Metal + O₂ → basic oxide (amphoteric: Al₂O₃, ZnO) | Non-metal + O₂ → acidic oxide
• Displacement: more reactive metal + salt of less reactive metal → new salt + less reactive metal
• Metal + dilute acid → Salt + H₂↑ (only above H in reactivity series)
• Extraction (reactive metals): concentration → oxide (calcination/roasting) → reduction → electrolytic refining
• Aqua regia: 3:1 conc. HCl : conc. HNO₃ — dissolves gold, platinum
• See full Chapter 3 Solutions

Chapter 4: Carbon and its Compounds

• Saturated (alkanes): CₙH₂ₙ⁺₂ | Unsaturated (alkenes): CₙH₂ₙ | (alkynes): CₙH₂ₙ−₂
• Test for unsaturation: bromine water decolourised = unsaturated
• Oxidation: alcohol → carboxylic acid (alkaline KMnO₄)
• See full Chapter 4 Solutions

Chapter 5: Periodic Classification of Elements

• Döbereiner’s Triads / Newlands’ Octaves: early (limited) attempts at classification by atomic mass
• Mendeleev’s law: properties are a periodic function of atomic mass; Modern law: periodic function of atomic number
• Modern Periodic Table: 18 groups, 7 periods; group = valence electrons, period = number of shells
• Trend across a period: atomic size ↓, metallic character ↓, valence electrons ↑
• Trend down a group: atomic size ↑, metallic character ↑ (metals), reactivity of non-metals ↓
• Not part of the current CBSE board syllabus (removed 2023-24), but see full Chapter 5 Solutions

Chapter 6: Life Processes

• Photosynthesis: 6CO₂+12H₂O →(sunlight, chlorophyll)→ C₆H₁₂O₆+6O₂+6H₂O
• Aerobic respiration: glucose+O₂ → CO₂+H₂O+energy (much more ATP)
• Anaerobic respiration: yeast: glucose → ethanol+CO₂+energy | muscle: glucose → lactic acid+energy
• Double circulation: deoxygenated blood: body→right atrium→right ventricle→lungs (pulmonary) | oxygenated blood: lungs→left atrium→left ventricle→body (systemic)
• Basic functional units: alveoli (lungs, gas exchange) | nephron (kidney, filtration)
• Xylem: water/minerals, upward, dead cells, passive | Phloem: food, bidirectional, living cells, active (ATP)
• See full Chapter 5 Solutions

Chapter 7: Control and Coordination

• Reflex arc: receptor → sensory neuron → relay neuron (spinal cord) → motor neuron → effector
• Neuron: dendrite (receive) → cell body → axon (transmit) → synapse (chemical gap)
• Brain regions: cerebrum (thinking/voluntary), cerebellum (balance/precision), medulla (involuntary — heartbeat, breathing)
• Plant hormones: auxin (growth/phototropism), gibberellin (stem growth), cytokinin (cell division), abscisic acid (inhibitor/stress), ethylene (ripening)
• Tropisms (directional, growth-based): phototropism, geotropism, hydrotropism, chemotropism  |  Nastic movements (non-directional): e.g. touch-me-not (turgor-based, no growth)
• See full Chapter 6 Solutions

Chapter 8: How do Organisms Reproduce?

• Asexual: fission, budding, fragmentation, regeneration, spore formation, vegetative propagation.
• Sexual: two parents, gametes, fertilisation, produces genetic variation.
• Male system: testis → vas deferens → seminal vesicle/prostate → urethra.
• Female system: ovary → fallopian tube → uterus → vagina.
• Contraception: barrier, hormonal, IUD, surgical — see full revision notes.

Chapter 9: Heredity and Evolution

• Monohybrid F2 ratio: 3:1 (phenotypic), 1:2:1 (genotypic)
• Dihybrid F2 ratio: 9:3:3:1
• Sex determination: XX = female, XY = male; fathers sperm determines sex
• Only germ-cell (egg/sperm) DNA changes are heritable; somatic/acquired traits are not

Chapter 10: Light: Reflection and Refraction

• f = R/2 (spherical mirrors)
• Mirror formula: 1/v + 1/u = 1/f; magnification m = -v/u
• Lens formula: 1/v – 1/u = 1/f; magnification m = v/u
• Power of lens: P = 1/f (f in metres), unit dioptre (D); combined power in contact = sum of individual powers
• Refractive index n = c/v

Chapter 11: The Human Eye and the Colourful World

• Power of lens, P = 1/f (f in metres, unit dioptre D)
• Lens formula: 1/f = 1/v − 1/u
• Concave lens (myopia correction) → negative power/focal length
• Convex lens (hypermetropia correction) → positive power/focal length
• Normal near point ≈ 25 cm; normal far point = infinity
• Full Chapter 10 Solutions →

Chapter 12: Electricity

• Ohm’s Law: V = IR
• Resistance: R = ρL/A
• Series: R_s = R₁+R₂+R₃+…
• Parallel: 1/R_p = 1/R₁+1/R₂+1/R₃+…
• Power: P = VI = I²R = V²/R
• Energy: E = Pt; 1 kWh = 3.6×10⁶ J
• Heat (Joule’s law): H = I²Rt

Chapter 13: Magnetic Effects of Electric Current

• Force on a conductor: F = BIL sinθ (max at θ=90°)
• Right-hand thumb rule: field around a straight current-carrying wire
• Fleming’s Left-Hand Rule: Field-Current-Motion (force direction)
• Fleming’s Right-Hand Rule: Motion-Field-Current (induced current direction)
• India domestic supply: 220V, 50Hz AC
• Full Chapter 12 Solutions →

Our Environment (Key Facts) — Legacy Chapter, Removed from Current Syllabus

• 10% Law: only ~10% of energy transfers to the next trophic level
• Food chains rarely exceed 3-5 trophic levels
• Ozone (O₃) in the stratosphere absorbs UV radiation; CFCs deplete it
• Montreal Protocol (1987) — global CFC phase-out agreement
• 3 R’s of waste management: Reduce, Reuse, Recycle
• Legacy Chapter Content (Removed from Syllabus) →

Written by Satish

NCERTBooks.org is an independent educational resource run by a small team focused on making official NCERT textbooks easy to find, read, and download for students, parents, and teachers across India. We are not affiliated with NCERT or the Ministry of Education -- we organise publicly available NCERT content by class and subject, verify links against official sources, and build tools (like our in-browser reader) that make studying more convenient. Every guide we publish is written and reviewed by our team based on the actual NCERT curriculum and syllabus.