CBSE Class 10 Science All Formulas List 2027 - Physics, Chemistry, Biology

In short: This is the complete list of all formulas, equations, and key terms you need for CBSE Class 10 Science 2027. Physics formulas cover Light and Electricity (the two most numerical-heavy chapters). Chemistry covers all important chemical equations. Biology covers key processes and terms. Bookmark this page and revise from it daily in the last month before exams.

How to Use This List

1. Print or bookmark this page. Use it as your daily revision sheet.
2. Physics formulas: Memorize and practice applying them in numerical problems.
3. Chemical equations: Write each equation 3-4 times to memorize. Always balance before moving to the next.
4. Biology terms: These are the key definitions and processes that appear as 1-3 mark questions.

Physics Formulas

Light - Reflection and Refraction (Chapter 10)

Mirror Formula: 1/v + 1/u = 1/f

Where: v = image distance, u = object distance, f = focal length

Magnification (Mirror): m = -v/u = h'/h

Where: h' = image height, h = object height

Relationship between focal length and radius of curvature: f = R/2

Snell's Law (Refractive index): n = sin i / sin r

Refractive index in terms of speed: n = speed of light in vacuum / speed of light in medium = c/v

Lens Formula: 1/v - 1/u = 1/f

Magnification (Lens): m = v/u = h'/h

Power of a lens: P = 1/f (in metres)

Unit: Dioptre (D). Convex lens has positive power, concave lens has negative power.

Sign Convention (New Cartesian):

• All distances measured from the optical centre (lens) or pole (mirror).
• Distances in the direction of incident light are positive.
• Distances against the direction of incident light are negative.
• Heights above the principal axis are positive, below are negative.

Electricity (Chapter 12)

Ohm's Law: V = IR

Where: V = potential difference (volts), I = current (amperes), R = resistance (ohms)

Resistance: R = ρL/A

Where: ρ = resistivity, L = length of conductor, A = cross-sectional area

Resistors in Series: R_total = R1 + R2 + R3 + ...

Current is same through all resistors. Voltage divides.

Resistors in Parallel: 1/R_total = 1/R1 + 1/R2 + 1/R3 + ...

Voltage is same across all resistors. Current divides.

Electric Power: P = VI = I²R = V²/R

Unit: Watt (W)

Electrical Energy: E = P × t = VIt

Unit: Joule (J) or kilowatt-hour (kWh)

1 kWh = 3.6 × 10⁶ J

Heating Effect of Current (Joule's Law): H = I²Rt

Where: H = heat produced in joules

Electric Charge: Q = It

Where: Q = charge in coulombs, I = current, t = time in seconds

Human Eye and Colourful World (Chapter 11)

Power of combination of lenses: P = P1 + P2

Angle of deviation through a prism: d = i1 + i2 - A

Where: A = angle of prism, i1 and i2 = angles of incidence and emergence

Magnetic Effects of Electric Current (Chapter 13)

Fleming's Left Hand Rule:

• Thumb: Direction of Force (motion)
• Index finger: Direction of Magnetic Field
• Middle finger: Direction of Current

Fleming's Right Hand Rule (for generators):

• Thumb: Direction of Motion
• Index finger: Direction of Magnetic Field
• Middle finger: Direction of Induced Current

Chemistry: Important Chemical Equations

Chemical Reactions and Equations (Chapter 1)

Combination Reactions:

• 2Mg + O₂ → 2MgO (burning magnesium)
• CaO + H₂O → Ca(OH)₂ (quicklime + water)
• C + O₂ → CO₂ (burning carbon)

Decomposition Reactions:

• 2FeSO₄ → Fe₂O₃ + SO₂ + SO₃ (thermal decomposition)
• CaCO₃ → CaO + CO₂ (limestone heating)
• 2Pb(NO₃)₂ → 2PbO + 4NO₂ + O₂ (lead nitrate heating)
• 2AgCl → 2Ag + Cl₂ (photodecomposition)
• 2H₂O → 2H₂ + O₂ (electrolysis)

Displacement Reactions:

• Fe + CuSO₄ → FeSO₄ + Cu
• Zn + CuSO₄ → ZnSO₄ + Cu
• Cu + 2AgNO₃ → Cu(NO₃)₂ + 2Ag

Double Displacement Reactions:

• Na₂SO₄ + BaCl₂ → BaSO₄↓ + 2NaCl
• NaOH + HCl → NaCl + H₂O (neutralization)

Redox Reactions:

• CuO + H₂ → Cu + H₂O (Cu is reduced, H₂ is oxidized)
• ZnO + C → Zn + CO (Zn is reduced, C is oxidized)

Acids, Bases and Salts (Chapter 2)

Acid + Metal → Salt + Hydrogen gas

• 2HCl + Zn → ZnCl₂ + H₂↑
• H₂SO₄ + Zn → ZnSO₄ + H₂↑

Acid + Metal Carbonate → Salt + CO₂ + Water

• 2HCl + Na₂CO₃ → 2NaCl + H₂O + CO₂↑
• 2HCl + CaCO₃ → CaCl₂ + H₂O + CO₂↑

Acid + Metal Hydrogen Carbonate → Salt + CO₂ + Water

• HCl + NaHCO₃ → NaCl + H₂O + CO₂↑

Acid + Base → Salt + Water (Neutralization)

• NaOH + HCl → NaCl + H₂O
• Ca(OH)₂ + H₂SO₄ → CaSO₄ + 2H₂O

Important Salt Reactions:

• NaCl + H₂SO₄ → NaHSO₄ + HCl
• Chlor-alkali process: 2NaCl(aq) + 2H₂O → 2NaOH + Cl₂ + H₂
• Baking soda: NaHCO₃ (Sodium hydrogen carbonate)
• Washing soda: Na₂CO₃.10H₂O
• Plaster of Paris: CaSO₄.½H₂O
• Gypsum: CaSO₄.2H₂O

Plaster of Paris setting: CaSO₄.½H₂O + 1½H₂O → CaSO₄.2H₂O

Metals and Non-Metals (Chapter 3)

Reactivity Series (most to least reactive): K > Na > Ca > Mg > Al > Zn > Fe > Ni > Sn > Pb > (H) > Cu > Hg > Ag > Au > Pt

Metal + Oxygen → Metal oxide

• 4Na + O₂ → 2Na₂O
• 2Mg + O₂ → 2MgO
• 4Al + 3O₂ → 2Al₂O₃

Metal + Water → Metal hydroxide + H₂

• 2Na + 2H₂O → 2NaOH + H₂↑
• Ca + 2H₂O → Ca(OH)₂ + H₂↑
• 2Al + 6H₂O → 2Al(OH)₃ + 3H₂↑ (with steam)

Metal + Dilute Acid → Salt + H₂

• Zn + 2HCl → ZnCl₂ + H₂↑
• Fe + H₂SO₄ → FeSO₄ + H₂↑

Extraction of metals:

• Highly reactive (Na, K, Ca, Al): Electrolytic reduction
• Moderately reactive (Zn, Fe, Pb): Carbon reduction
  • ZnO + C → Zn + CO
  • Fe₂O₃ + 3C → 2Fe + 3CO
• Least reactive (Cu, Ag, Au): Found free or simple heating
  • 2HgS + 3O₂ → 2HgO + 2SO₂, then 2HgO → 2Hg + O₂

Corrosion: 4Fe + 3O₂ + xH₂O → 2Fe₂O₃.xH₂O (rust)

Carbon and Its Compounds (Chapter 4)

Combustion of ethanol: C₂H₅OH + 3O₂ → 2CO₂ + 3H₂O

Oxidation of ethanol: C₂H₅OH + alkaline KMnO₄ or acidified K₂Cr₂O₇ → CH₃COOH (ethanoic acid)

Dehydration of ethanol: C₂H₅OH → (conc. H₂SO₄, 443K) → C₂H₄ + H₂O

Esterification: CH₃COOH + C₂H₅OH → (acid catalyst) → CH₃COOC₂H₅ + H₂O

Saponification: CH₃COOC₂H₅ + NaOH → CH₃COONa + C₂H₅OH

Homologous series general formulae:

• Alkanes: CₙH₂ₙ₊₂ (single bonds only)
• Alkenes: CₙH₂ₙ (one double bond)
• Alkynes: CₙH₂ₙ₋₂ (one triple bond)

Biology: Key Terms and Processes

Life Processes (Chapter 5)

Photosynthesis equation: 6CO₂ + 6H₂O → (sunlight, chlorophyll) → C₆H₁₂O₆ + 6O₂

Aerobic respiration: C₆H₁₂O₆ + 6O₂ → 6CO₂ + 6H₂O + Energy (ATP)

Anaerobic respiration (in yeast - fermentation): C₆H₁₂O₆ → 2C₂H₅OH + 2CO₂ + Energy

Anaerobic respiration (in muscles): C₆H₁₂O₆ → 2C₃H₆O₃ (lactic acid) + Energy

Key terms:

• Autotrophic nutrition: Organisms make their own food (plants)
• Heterotrophic nutrition: Organisms depend on others (animals)
• Peristalsis: Rhythmic contraction of alimentary canal muscles
• Double circulation: Blood passes through heart twice in one complete cycle
• Transpiration: Loss of water from aerial parts of plants (mainly stomata)
• Translocation: Transport of food (sucrose) through phloem
• Excretion: Removal of metabolic waste products

How Do Organisms Reproduce (Chapter 8)

Asexual reproduction methods:

• Fission: Amoeba (binary), Plasmodium (multiple)
• Budding: Hydra, yeast
• Fragmentation: Spirogyra
• Regeneration: Planaria
• Vegetative propagation: Bryophyllum (leaves), potato (tuber), rose (stem cutting)
• Spore formation: Rhizopus

Heredity and Evolution (Chapter 9)

Mendel's monohybrid cross ratio: 3:1 (phenotypic), 1:2:1 (genotypic) Mendel's dihybrid cross ratio: 9:3:3:1

Sex determination: XX = Female, XY = Male

Our Environment (Chapter 15)

10% energy rule: Only 10% of energy is transferred to the next trophic level.

Ozone formation: 3O₂ → (UV) → 2O₃

Quick Revision Tips

1. Physics: Write all formulas on a card and carry it with you. Practice at least 5 numericals daily from Light and Electricity.
2. Chemistry: Write each equation 3 times. Focus on balancing and identifying reaction types.
3. Biology: Focus on processes (photosynthesis, respiration, circulation) and be able to explain each step.
4. Units matter: Always write units in Physics numerical answers. "R = 5" scores zero. "R = 5 Ω" scores full marks.
5. Sign convention: Practice the New Cartesian Sign Convention until it becomes automatic.

For chapter-wise marks distribution, see our CBSE Class 10 Science marks weightage guide. For Maths formulas, see the CBSE Class 10 Maths formulas complete list.

Frequently Asked Questions

How many formulas do I need to learn for CBSE Class 10 Science?

For Physics, there are about 15-20 key formulas across Light and Electricity. For Chemistry, you need to memorize approximately 30-35 balanced equations. Biology has fewer formulas but requires learning key processes and definitions. This list covers all of them.

Which Physics chapter has the most formulas?

Electricity (Chapter 12) has the most formulas with Ohm's Law, power formulas, resistance combinations, and Joule's law. Light (Chapter 10) comes second with mirror formula, lens formula, magnification, and Snell's law.

Do I need to memorize all chemical equations?

Yes. Chemical equations appear in every paper. You need to know the equation, its type (combination, decomposition, etc.), and be able to balance it. Start with Chapter 1 equations, then move to Acids/Bases/Salts and Metals/Non-Metals.

How should I revise formulas before the exam?

In the last month, spend 15 minutes every morning writing all Physics formulas and 15 minutes writing chemical equations from memory. Check against this list and note which ones you miss. Focus on those the next day.

Are Biology diagrams as important as formulas?

Yes. While Biology has fewer mathematical formulas, diagrams are equally critical. The human heart, nephron, stomata, neuron, and reproductive system diagrams each carry 2-5 marks. Practice drawing them alongside formula revision.

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