CBSE Class 10 Science: Chapter-Wise Revision Notes

These organized notes cover all 16 chapters of CBSE Class 10 Science, designed for efficient revision before the board exam.

Chapter 1: Chemical Reactions and Equations

Types of Reactions

  • Combination: A + B → AB
  • Decomposition: AB → A + B
  • Displacement: A + BC → AC + B
  • Double Displacement: AB + CD → AD + CB

Key Concepts: Balanced equations (law of conservation of mass), Redox reactions (Oxidation = loss of electrons, Reduction = gain of electrons).

Chapter 2: Acids, Bases and Salts

  • Acid: Produces H+ ions (e.g., HCl)
  • Base: Produces OH- ions (e.g., NaOH)
  • pH Scale: Below 7 = Acid, Equal to 7 = Neutral, Above 7 = Base
  • Neutralization: Acid + Base → Salt + Water

Chapter 3: Metals and Non-metals

Metals: Good conductors, malleable, ductile. Non-metals: Poor conductors, brittle. The reactivity series determines displacement reactions.

Chapter 4: Carbon and Its Compounds

Carbon exhibits tetravalency and catenation (chain formation). Important functional groups include alcohol (-OH) and carboxylic acid (-COOH).

Chapter 5: Periodic Classification of Elements

The Modern Periodic Table is based on atomic number. Key trends: atomic size, metallic character, and valency vary across groups (columns) and periods (rows).

Chapter 6: Life Processes

Four essential processes: Nutrition (autotrophic vs. heterotrophic), Respiration (aerobic vs. anaerobic), Transportation, and Excretion.

Chapter 7: Control and Coordination

The nervous system (brain, spinal cord, nerves) provides quick responses, while hormones (chemical messengers from endocrine glands) provide slower but longer-lasting coordination.

Chapter 8: How Do Organisms Reproduce

  • Asexual: Binary fission, budding, fragmentation
  • Sexual: Involves male and female reproductive systems, fertilization

Chapter 9: Heredity and Evolution

Mendel's Laws: Dominant and recessive traits inheritance. Evolution: Gradual changes in species over time through natural selection.

Chapter 10: Light — Reflection and Refraction

  • Reflection: Angle of incidence = Angle of reflection
  • Refraction: Bending of light when passing between media
  • Mirror types: Concave (converging) and Convex (diverging)

Chapter 11: Human Eye and Colourful World

Eye defects: Myopia (short-sightedness) and Hypermetropia (far-sightedness). Dispersion: White light splitting into colors (rainbow).

Chapter 12: Electricity

  • Ohm's Law: V = IR
  • Key concepts: Resistance, series and parallel circuits, power calculations

Chapter 13: Magnetic Effects of Electric Current

Current-carrying conductors produce magnetic fields. Applications include electric motors and electromagnets.

Chapters 14-16: Energy, Environment & Natural Resources

  • Energy Sources: Renewable (solar, wind) vs. Non-renewable (coal, petroleum)
  • Ecosystem: Food chains, biotic and abiotic components
  • Conservation: Reduce, Reuse, Recycle

Board Exam Tips

  1. Focus on NCERT examples and diagrams
  2. Practice numerical problems (Electricity and Light chapters)
  3. Revise chemical reactions and definitions daily
  4. Solve previous year question papers regularly

Chapter-wise FAQs (Questions + Short Answers)

Chapter 1: Chemical Reactions and Equations

Q1. What is a chemical reaction?

Conversion of reactants into new substances (products).

Q2. What is a balanced equation?

Equal number of atoms on both sides.

Q3. What is oxidation?

Loss of electrons or gain of oxygen.

Q4. What is reduction?

Gain of electrons or loss of oxygen.

Q5. What is corrosion?

Damage of metal due to air and moisture.

Chapter 2: Acids, Bases and Salts

Q1. What are acids?

Substances that release H⁺ ions in solution.

Q2. What are bases?

Substances that release OH⁻ ions.

Q3. What is pH?

Measure of acidity/basicity (0–14 scale).

Q4. What is neutralization?

Acid + Base → Salt + Water.

Q5. What is a salt?

Product of neutralization reaction.

Chapter 3: Metals and Non-Metals

Q1. What are metals?

Good conductors of heat and electricity.

Q2. What are non-metals?

Poor conductors, brittle.

Q3. What is reactivity series?

List of metals in decreasing reactivity.

Q4. What is corrosion?

Rusting of metals.

Q5. What are ionic compounds?

Compounds formed by transfer of electrons.

Chapter 4: Carbon and Its Compounds

Q1. Why is carbon special?

Forms large number of compounds (catenation).

Q2. What are covalent bonds?

Bonds formed by sharing electrons.

Q3. What are hydrocarbons?

Compounds of carbon and hydrogen.

Q4. What is homologous series?

Group of compounds with same functional group.

Q5. What are soaps and detergents?

Cleaning agents.

Chapter 5: Periodic Classification of Elements

Q1. What is periodic table?

Arrangement of elements by atomic number.

Q2. What are groups?

Vertical columns.

Q3. What are periods?

Horizontal rows.

Q4. What is valency?

Combining capacity of an element.

Q5. What are periodic trends?

Patterns in properties across table.

Chapter 6: Life Processes

Q1. What are life processes?

Basic functions like nutrition and respiration.

Q2. What is photosynthesis?

Process of making food using sunlight.

Q3. What is respiration?

Breakdown of food to release energy.

Q4. What is transportation?

Movement of substances in body.

Q5. What is excretion?

Removal of waste.

Chapter 7: Control and Coordination

Q1. What is nervous system?

System that controls body activities.

Q2. What are hormones?

Chemical messengers.

Q3. What is reflex action?

Quick automatic response.

Q4. What is coordination?

Working together of body parts.

Q5. What is endocrine system?

Hormone-secreting system.

Chapter 8: How do Organisms Reproduce?

Q1. What is reproduction?

Process of producing offspring.

Q2. What is asexual reproduction?

One parent involved.

Q3. What is sexual reproduction?

Two parents involved.

Q4. What is fertilization?

Fusion of gametes.

Q5. Why is reproduction important?

Continuity of species.

Chapter 9: Heredity and Evolution

Q1. What is heredity?

Passing traits from parents to offspring.

Q2. What is gene?

Unit of inheritance.

Q3. Who was Mendel?

Father of genetics.

Q4. What is evolution?

Gradual change in species.

Q5. What is natural selection?

Survival of fittest.

Chapter 10: Light – Reflection and Refraction

Q1. What is reflection?

Bouncing back of light.

Q2. What is refraction?

Bending of light.

Q3. What is focal length?

Distance from lens to focus.

Q4. What is refractive index?

Measure of bending of light.

Q5. What are lenses?

Optical devices.

Chapter 11: Human Eye and Colourful World

Q1. What is retina?

Light-sensitive part of eye.

Q2. What is myopia?

Near-sightedness.

Q3. What is hypermetropia?

Far-sightedness.

Q4. What is dispersion?

Splitting of light.

Q5. Why is sky blue?

Scattering of light.

Chapter 12: Electricity

Q1. What is electric current?

Flow of charge.

Q2. What is voltage?

Potential difference.

Q3. What is resistance?

Opposition to current.

Q4. What is Ohm’s Law?

V = IR.

Q5. What is electric power?

Rate of energy consumption.

Chapter 13: Magnetic Effects of Electric Current

Q1. What is magnetic field?

Region around magnet.

Q2. What is electromagnet?

Temporary magnet using current.

Q3. What is electric motor?

Converts electrical energy to mechanical.

Q4. What is generator?

Converts mechanical to electrical.

Q5. What is electromagnetic induction?

Production of current by changing magnetic field.

Chapter 14: Sources of Energy

Q1. What are renewable resources? Can be replenished.

Q2. What are non-renewable resources?

Limited resources.

Q3. What is solar energy?

Energy from sun.

Q4. What is wind energy?

Energy from wind.

Q5. What is biogas?

Fuel from organic waste.

Chapter 15: Our Environment

Q1. What is ecosystem?

Interaction of living and non-living things.

Q2. What is food chain?

Sequence of energy transfer.

Q3. What are decomposers?

Break down dead matter.

Q4. What is pollution?

Harmful changes in environment.

Q5. What is ozone layer?

Protects from UV rays.

Chapter 16: Sustainable Management of Natural Resources

Q1. What is sustainable development?

Use resources without harming future.

Q2. What are natural resources?

Resources from nature.

Q3. What is water conservation?

Saving water.

Q4. What are 3Rs?

Reduce, Reuse, Recycle.

Q5. Why conserve forests?

Maintain ecological balance.

CBSE Class 10 Science – Chapter-wise MCQs

Chapter 1: Chemical Reactions and Equations

1. Which of the following is a combination reaction?

    a) CaO + H₂O → Ca(OH)₂
    b) Zn + HCl → ZnCl₂ + H₂
    c) AgNO₃ + NaCl → AgCl + NaNO₃
    d) CaCO₃ → CaO + CO₂
Answer: a

2. What type of reaction is respiration?

    a) Endothermic
    b) Exothermic
    c) Displacement
    d) Decomposition
Answer: b

3. Which substance is oxidized in the reaction: Zn + CuSO₄ → ZnSO₄ + Cu?

    a) Zn
    b) Cu
    c) SO₄
    d) CuSO₄
Answer: a

Chapter 2: Acids, Bases and Salts

1. What is the pH of a neutral solution?

    a) 0
    b) 7
    c) 14
    d) 1
Answer: b

2. Which acid is present in lemon?

    a) Hydrochloric acid
    b) Sulfuric acid
    c) Citric acid
    d) Nitric acid
Answer: c

3. Which of the following is a base?

    a) NaCl
    b) HCl
    c) NaOH
    d) CO₂
Answer: c

Chapter 3: Metals and Non-Metals

1. Which metal reacts with cold water?

    a) Iron
    b) Copper
    c) Sodium
    d) Silver
Answer: c

2. Which property is not shown by metals?

    a) Ductility
    b) Malleability
    c) Brittleness
    d) Conductivity
Answer: c

3. Which is an ionic compound?

    a) CH₄
    b) CO₂
    c) NaCl
    d) H₂O
Answer: c

Chapter 4: Carbon and Its Compounds

1. Carbon forms covalent bonds because:

    a) It gains electrons
    b) It loses electrons
    c) It shares electrons
    d) It transfers electrons
Answer: c

2. Which is a saturated hydrocarbon?

    a) Ethene
    b) Ethyne
    c) Ethane
    d) Benzene
Answer: c

Chapter 5: Periodic Classification of Elements

1. Modern periodic table is based on:

    a) Atomic mass
    b) Atomic number
    c) Density
    d) Valency
Answer: b

2. Number of periods in periodic table:

    a) 5
    b) 6
    c) 7
    d) 8
Answer: c

Chapter 6: Life Processes

1. Photosynthesis occurs in:

    a) Mitochondria
    b) Chloroplast
    c) Nucleus
    d) Cytoplasm
Answer: b

2. Main function of stomata:

    a) Digestion
    b) Respiration
    c) Gas exchange
    d) Circulation
Answer: c

Chapter 7: Control and Coordination

1. The brain is part of:

    a) Digestive system
    b) Nervous system
    c) Circulatory system
    d) Respiratory system
Answer: b

2. Chemical messengers in the body are called:

    a) Enzymes
    b) Hormones
    c) Vitamins
    d) Minerals
Answer: b

Chapter 8: How do Organisms Reproduce?

1. Binary fission occurs in:

    a) Human
    b) Amoeba
    c) Plants
    d) Birds
Answer: b

2. Sexual reproduction involves:

    a) One parent
    b) Two parents
    c) No parent
    d) Multiple cells only
Answer: b

Chapter 9: Heredity and Evolution

1. Unit of heredity is:

    a) Cell
    b) Gene
    c) Tissue
    d) Organ
Answer: b

2. Father of genetics:

    a) Darwin
    b) Mendel
    c) Lamarck
    d) Watson
Answer: b

Chapter 10: Light – Reflection and Refraction

1. Laws of reflection are:

    a) 1
    b) 2
    c) 3
    d) 4
Answer: b

2. Unit of focal length:

    a) Meter
    b) Watt
    c) Volt
    d) Ampere
Answer: a

Chapter 11: Human Eye and Colourful World

1. Defect causing difficulty in seeing distant objects:

    a) Myopia
    b) Hypermetropia
    c) Presbyopia
    d) Astigmatism
Answer: a

Chapter 12: Electricity

1. Unit of electric current:

    a) Volt
    b) Ampere
    c) Ohm
    d) Watt
Answer: b

2. Ohm’s Law states:

    a) V = IR
    b) I = V²
    c) R = VI
    d) P = VI
Answer: a

Chapter 13: Magnetic Effects of Electric Current

1. Fleming’s right-hand rule is used for:

    a) Motor
    b) Generator
    c) Battery
    d) Resistor
Answer: b

Chapter 14: Sources of Energy

1. Renewable source of energy:

    a) Coal
    b) Petroleum
    c) Solar
    d) Natural gas
Answer: c

Chapter 15: Our Environment

1. Decomposers include:

    a) Plants
    b) Animals
    c) Bacteria
    d) Humans
Answer: c

Chapter 16: Sustainable Management of Natural Resources

1. 3Rs stand for:

    a) Reduce, Reuse, Recycle
    b) Read, Write, Repeat
    c) Run, Rest, Relax
    d) Remove, Repair, Replace
Answer: a Class 10 Science – Chapter 1: Chemical Reactions and Equations

How to Answer (CBSE Format)

Choose the correct option: a) Both A and R are true, and R is the correct explanation of A b) Both A and R are true, but R is NOT the correct explanation of A c) A is true, but R is false d) A is false, but R is true

Assertion–Reason Q&A

1.
    Assertion (A): Rusting of iron is a chemical change.
    Reason (R): A new substance (iron oxide) is formed.
Answer: a 2.
    Assertion (A): Chemical equations must be balanced.
    Reason (R): Mass is neither created nor destroyed in a reaction.
Answer: a 3.
    Assertion (A): In a displacement reaction, a more reactive element replaces a less reactive one.
    Reason (R): Reactivity series determines displacement.
Answer: a 4.
    Assertion (A): Burning of magnesium is an exothermic reaction.
    Reason (R): Heat energy is released during combustion.
Answer: a 5.
    Assertion (A): Decomposition reactions require energy.
    Reason (R): Bonds in compounds need energy to break.
Answer: a 6.
    Assertion (A): Oxidation involves loss of electrons.
    Reason (R): Reduction involves gain of electrons.
Answer: b 7.
    Assertion (A): Corrosion is a harmful process.
    Reason (R): It weakens metals over time.
Answer: a 8.
    Assertion (A): Rancidity affects food quality.
    Reason (R): It is caused by oxidation of fats and oils.
Answer: a 9.
    Assertion (A): All combination reactions are exothermic.
    Reason (R): Heat is always released in combination reactions.
Answer: c 10.
    Assertion (A): In redox reactions, oxidation and reduction occur together.
    Reason (R): One substance loses electrons while another gains electrons.
Answer: a 11.
    Assertion (A): Silver chloride forms a white precipitate.
    Reason (R): It is insoluble in water.
Answer: a 12.
    Assertion (A): Hydrogen gas burns with a pop sound.
    Reason (R): It is highly inflammable.
Answer: a 13.
    Assertion (A): A catalyst changes the rate of reaction.
    Reason (R): It is consumed during the reaction.
Answer: c 14.
    Assertion (A): Endothermic reactions absorb heat.
    Reason (R): Energy is required to break bonds.
Answer: a 15.
    Assertion (A): In Zn + CuSO₄ → ZnSO₄ + Cu, copper is displaced.
    Reason (R): Zinc is more reactive than copper.
Answer: a 16.
    Assertion (A): Balanced equations follow conservation of mass.
    Reason (R): Atoms are rearranged but not created or destroyed.
Answer: a 17.
    Assertion (A): Rusting requires oxygen and water.
    Reason (R): Dry air alone cannot cause rusting.
Answer: a 18.
    Assertion (A): Double displacement reactions often form precipitates.
    Reason (R): Insoluble products are formed.
Answer: a 19.
    Assertion (A): Oxidizing agents gain electrons.
    Reason (R): They get reduced during the reaction.
Answer: a 20.
    Assertion (A): Reduction is the opposite of oxidation.
    Reason (R): Reduction involves loss of electrons.
Answer: c

Keywords: Class 10 science notes, CBSE science, chemical reactions, acids bases salts, electricity Class 10, light reflection refraction, life processes, heredity evolution, board exam science notes