CBSE 10th Science Important Questions Chapter-Wise: Physics, Chemistry, Biology Guide

CBSE Class 10 Science is based entirely on NCERT textbooks. This chapter-wise guide covers the most important questions and concepts from each chapter, aligned with NCERT and CBSE exam pattern.

Why NCERT is Crucial for CBSE Science

1. Exam Pattern Alignment

CBSE Board Exam Pattern (Class 10 Science - 80 marks theory):

Question Type	Marks per Question	Number of Questions	Total Marks
Very Short Answer	1 mark	6 questions	6 marks
Short Answer I	2 marks	6 questions	12 marks
Short Answer II	3 marks	6 questions	18 marks
Long Answer	5 marks	3 questions	15 marks
Practical-based	Various	4-5 questions	~29 marks (integrated)

NCERT Coverage: 70-80% of questions are directly from NCERT textbook or its exercises. The remaining 20-30% are based on NCERT concepts with slight variations.

2. Question Distribution by Chapter

Chapter	Approx. Marks	Weightage
Chemical Reactions and Equations	8-10 marks	High
Acids, Bases and Salts	6-8 marks	High
Metals and Non-metals	4-6 marks	Medium
Carbon and Its Compounds	10-12 marks	Very High
Life Processes	8-10 marks	High
Control and Coordination	6-8 marks	Medium
How do Organisms Reproduce?	6-8 marks	Medium
Heredity and Evolution	8-10 marks	High
Light - Reflection and Refraction	8-10 marks	High
The Human Eye and the Colourful World	6-8 marks	Medium
Electricity	8-10 marks	High
Magnetic Effects of Electric Current	6-8 marks	Medium
Sources of Energy	3-5 marks	Low
Our Environment	3-5 marks	Low
Management of Natural Resources	3-5 marks	Low

Chapter-Wise Important Questions

1. Chemical Reactions and Equations

Key Concepts:

• Balancing chemical equations
• Types of chemical reactions (combination, decomposition, displacement, double displacement, oxidation-reduction)
• Oxidation and reduction (gain/loss of oxygen, hydrogen, or electrons)
• Corrosion and rancidity

Important Questions:

1. Balance the following equation: Fe + Hâ‚‚O → Fe₃Oâ‚„ + Hâ‚‚
2. Classify the reaction: Zn + Hâ‚‚SOâ‚„ → ZnSOâ‚„ + Hâ‚‚ (type and reason)
3. What happens when: (a) Dilute Hâ‚‚SOâ‚„ is added to Cu? (b) Iron rusts? (c) Marble reacts with acid?
4. Define: Oxidation and reduction with one example each
5. Short answer: Why is rancidity called oxidation? Give one example.

Expected Questions (2026 pattern):

• 1 very short answer (1 mark): Define oxidation/reduction
• 1 short answer (2 marks): Types of chemical reactions with examples
• 1 short answer (3 marks): Balancing equations and corrosion prevention
• 1 long answer (5 marks): Complete NCERT in-text questions and exercises

2. Acids, Bases and Salts

Key Concepts:

• pH scale (0-14), pH of acidic, basic, neutral solutions
• Natural indicators (litmus, red cabbage, turmeric)
• Preparation, properties and uses of Sodium Hydroxide, Bleaching Powder, Baking Soda, Washing Soda, Plaster of Paris
• Hydrogen carbonate indicator
• Metal oxides and non-metal oxides reactions with acids and bases

Important Questions:

1. What is pH? Scale of 0-14, pH of acidic, basic, neutral solutions
2. Which indicator changes colour in acidic/basic medium? Name natural indicators.
3. Write the formula and uses of: Baking Soda, Washing Soda, Plaster of Paris
4. Neutralisation reaction: Explain with one example and its daily life application
5. pH of household items: Which are acidic, basic, neutral? (Toothpaste, soap, lemon juice, water, gastric juice)

Expected Questions:

• 1 very short answer (1 mark): Name the pH of distilled water
• 1 short answer (2 marks): Natural indicators and their source
• 1 short answer (3 marks): Prepare baking soda, washing soda, Plaster of Paris (NCERT in-text)
• 1 long answer (5 marks): Complete NCERT exercise questions (3-4 questions)

3. Metals and Non-metals

Key Concepts:

• Physical and chemical properties of metals and non-metals
• Reactivity series
• Formation and properties of ionic compounds
• Extraction of metals (concentration, roasting, calcination)
• Corrosion prevention methods

Important Questions:

1. Define: Reactivity series, ionic compound, corrosion
2. Place the following in decreasing reactivity: K, Na, Ca, Mg, Al, Zn, Fe, Cu, Hg, Ag, Au
3. Why do metals conduct electricity? Non-metals do not?
4. Formation of ionic compound with example (NaCl) - electron transfer
5. Two methods of corrosion prevention

Expected Questions:

• 1 very short answer (1 mark): Define corrosion
• 1 short answer (2 marks): Reactivity series concept
• 1 short answer (3 marks): Ionic compound formation and properties
• 1 long answer (5 marks): Extraction of aluminium or iron (complete process)

4. Carbon and Its Compounds

Key Concepts:

• Covalent bonding, versatile nature of carbon
• Homologous series, functional groups
• Alkanes, Alkenes, Alkynes (general formula, properties)
• Ethanol and Ethanoic acid (chemical properties, uses)
• Soaps and detergents (cleaning action)
• Soap mechanism (micelle formation)

Important Questions:

1. Why is carbon called the “backbone of organic compounds”?
2. Write the general formula for alkane, alkene, alkyne
3. Difference between ethane and ethene, ethanol and ethanoic acid
4. Chemical properties of ethanol (oxidation, combustion, action of Na)
5. Soap mechanism: How does soap clean? Micelle formation explanation

Expected Questions:

• 1 very short answer (1 mark): General formula of alkene
• 1 short answer (2 marks): Ethanol vs ethanoic acid (taste, smell, litmus test)
• 1 short answer (3 marks): Chemical properties of ethanol (any 2)
• 1 long answer (5 marks): Soap mechanism (micelle formation) or complete NCERT exercise

5. Life Processes

Key Concepts:

• Nutrition: Autotrophic, heterotrophic, photosynthesis equation
• Respiration: Aerobic and anaerobic, cellular respiration equation
• Transportation: Human circulatory system (heart, blood vessels, blood), plant transport (xylem, phloem)
• Excretion: Human excretory system (kidneys, urine formation), plant excretion

Important Questions:

1. Write the photosynthesis equation: 6COâ‚‚ + 6Hâ‚‚O → C₆H₁₂O₆ + 6Oâ‚‚ (light, chlorophyll)
2. Difference between aerobic and anaerobic respiration
3. Human circulatory system: Structure of heart, double circulation, blood circulation path
4. Excretion in humans: Nephron structure, urine formation process
5. Difference between auto- and heterotrophic nutrition

Expected Questions:

• 1 very short answer (1 mark): Products of photosynthesis
• 1 short answer (2 marks): Aerobic vs anaerobic respiration
• 1 short answer (3 marks): Human excretory system diagram and function
• 1 long answer (5 marks): Complete any NCERT exercise question (3-4 questions)

6. Control and Coordination

Key Concepts:

• Nervous system: Brain, spinal cord, nerves, reflex action
• Hormonal system: Pituitary, thyroid, adrenal glands, hormones
• Plant tropisms: Phototropism, geotropism, plant hormones (auxin)

Important Questions:

1. Reflex arc: Brain, spinal cord, sensory neuron, motor neuron, effector
2. Difference between nervous and hormonal control
3. Human brain: Forebrain, midbrain, hindbrain functions
4. Plant hormones: Auxin, phototropism and geotropism examples
5. Types of nerves: Sensory, motor, mixed nerves

Expected Questions:

• 1 very short answer (1 mark): Name the part of brain that controls balance
• 1 short answer (2 marks): Difference between nervous and hormonal control
• 1 short answer (3 marks): Reflex arc diagram and explanation
• 1 long answer (5 marks): Human brain parts and functions or plant tropism explanation

7. How do Organisms Reproduce?

Key Concepts:

• Asexual reproduction: Binary fission, budding, fragmentation, spore formation
• Sexual reproduction: Male and female reproductive systems, menstrual cycle
• Fertilisation: Internal and external, zygote formation
• Reproductive health: STIs, contraception (as per CBSE syllabus)

Important Questions:

1. Binary fission vs fragmentation vs spore formation examples
2. Male reproductive system: Structure of testis, sperm production, semen
3. Female reproductive system: Structure of ovary, egg, uterus, menstrual cycle (28 days)
4. Fertilisation: Internal vs external, zygote formation and implantation
5. Reproductive health: Brief concept of safe/unsafe periods (NCERT level only)

Expected Questions:

• 1 very short answer (1 mark): Name asexual reproduction method in Amoeba
• 1 short answer (2 marks): Difference between sexual and asexual reproduction
• 1 short answer (3 marks): Male reproductive system parts and functions
• 1 long answer (5 marks): Menstrual cycle (28 days) or fertilisation and implantation

8. Heredity and Evolution

Key Concepts:

• Mendel’s laws: Law of segregation, law of independent assortment
• Dominant and recessive traits, monohybrid cross, dihybrid cross
• Evolution: Fossils, evolutionary relationships, human evolution (brief)
• Speciation, extinction, survival of fittest

Important Questions:

1. Mendel’s law of segregation with example (tall/dwarf pea plant)
2. Monohybrid cross: TT × tt F1 generation, F2 generation ratio (3:1)
3. Fossils: What are they? What do they tell about evolution?
4. Human evolution: Brief ( Australopithecus, Homo habilis, Homo erectus, Homo sapiens)
5. Speciation: Definition and process

Expected Questions:

• 1 very short answer (1 mark): Define gene, chromosome
• 1 short answer (2 marks): Mendel’s law of segregation
• 1 short answer (3 marks): Monohybrid cross F2 generation ratio explanation
• 1 long answer (5 marks): Human evolution timeline or complete NCERT exercise

9. Light - Reflection and Refraction

Key Concepts:

• Laws of reflection, image formation by plane mirror
• Image formation by concave and convex mirrors (ray diagrams)
• Laws of refraction, refractive index
• Image formation by concave and convex lenses (ray diagrams)
• Power of lens (P = 1/f in metres, unit: dioptre)
• Human eye: Structure, accommodation, defects (myopia, hypermetropia, presbyopia) and corrections

Important Questions:

1. Laws of reflection and refraction statement
2. Image by plane mirror: Characteristics (virtual, erect, same size)
3. Concave mirror: When image is at infinity, at focus, between focus and pole, magnified, diminished
4. Convex mirror: Always produces virtual, erect, diminished image; uses (rear-view mirror)
5. Lens formula: 1/f = 1/v + 1/u, magnification m = v/u
6. Human eye defects: Myopia (cause, correction with convex/concave lens), Hypermetropia, Presbyopia

Expected Questions:

• 1 very short answer (1 mark): Refractive index definition
• 1 short answer (2 marks): Difference between concave and convex lens image nature
• 1 short answer (3 marks): Lens formula derivation or derivation of magnification
• 1 long answer (5 marks): Human eye structure, accommodation, and any two defect corrections with ray diagrams

10. The Human Eye and the Colourful World

Key Concepts:

• Dispersion of white light by glass prism, VIBGYOR spectrum
• Atmospheric refraction, scattering of light (why sky is blue, sunrise/sunset red)
• Tyndall effect
• Rainbow formation
• Colour of sun at sunrise/sunset

Important Questions:

1. Dispersion of light: White light through glass prism, VIBGYOR order
2. Why is sky blue? Scattering of light (Rayleigh scattering explanation)
3. Why is sun red at sunrise/sunset? Scattering and distance effect
4. Tyndall effect: Explanation and one daily life example
5. Rainbow formation: Conditions required (sun behind observer, rain in front)

Expected Questions:

• 1 very short answer (1 mark): Name the seven colours of VIBGYOR
• 1 short answer (2 marks): Why does sky appear blue?
• 1 short answer (3 marks): Scattering of light and its applications
• 1 long answer (5 marks): Dispersion of white light through prism, rainbow formation, or atmospheric refraction

11. Electricity

Key Concepts:

• Electric current, potential difference, resistance, Ohm’s law (V = IR)
• Factors affecting resistance (length, area, temperature, material)
• Series and parallel resistor combinations
• Power and energy formulas (P = VI, P = I²R, H = I²Rt)
• Heating effect of electric effect, practical applications

Important Questions:

1. State Ohm’s law and define resistance, resistivity
2. Series vs parallel resistor combination: Differences in current, voltage, resistance
3. Calculate: Total resistance of 3 resistors in series/parallel
4. Power relation: P = VI, P = I²R, derive H = I²Rt (Joule’s heating)
5. Example: An electric heater of 1000 W used for 2 hours daily for 30 days, calculate energy consumed and cost

Expected Questions:

• 1 very short answer (1 mark): Unit of electrical energy (kWh)
• 1 short answer (2 marks): Series vs parallel combination differences
• 1 short answer (3 marks): Solve numerical on resistance, current, or power
• 1 long answer (5 marks): Complete NCERT exercise questions (2-3 numerical-based questions)

12. Magnetic Effects of Electric Current

Key Concepts:

• Magnetic field, magnetic field lines, properties
• Magnetic field due to current-carrying conductor, circular coil, solenoid
• Force on current-carrying conductor in magnetic field (Fleming’s left hand rule)
• Electromagnetic induction (induced current, Fleming’s right hand rule)
• Electric generator and electric motor (basic principle, difference)

Important Questions:

1. Magnetic field lines: Properties, how to draw around current-carrying conductor
2. Right hand thumb rule vs Fleming’s left hand rule (difference and use)
3. Electromagnetic induction: Principle of electric generator
4. Electric motor: Principle, working, Fleming’s left hand rule application
5. Overloading and short-circuiting: Causes and prevention

Expected Questions:

• 1 very short answer (1 mark): Name the rule for direction of magnetic field around conductor
• 1 short answer (2 marks): Difference between generator and motor
• 1 short answer (3 marks): Electromagnetic induction principle or Fleming’s right hand rule
• 1 long answer (5 marks): Electric motor diagram, working, or generator principle and construction

13. Sources of Energy

Key Concepts:

• Conventional: Coal, petroleum, natural gas, nuclear energy
• Non-conventional/solar: Solar energy, wind energy, hydro energy, biogas, geothermal
• Advantages and disadvantages of each
• Environmental impact, climate change, future energy needs

Important Questions:

1. Difference between conventional and non-conventional energy sources
2. Solar energy: Solar panel working, solar cooker, solar water heater
3. Wind energy: Windmill working, advantages, limitations
4. Hydro energy: Dam, reservoir, turbine, advantages, limitations
5. Biogas: Raw material, production, uses, advantages

Expected Questions:

• 1 very short answer (1 mark): Name one non-conventional energy source
• 1 short answer (2 marks): Advantage of solar energy over conventional
• 1 short answer (3 marks): Solar energy limitations or biogas production process
• 1 long answer (5 marks): Complete any NCERT exercise question or environmental impact of energy sources

13. Our Environment

Key Concepts:

• Food chains and food webs, trophic levels
• 10% law of energy transfer
• Ozone layer, ozone depletion, holes in ozone layer
• Waste management: 3R (Reduce, Reuse, Recycle)
• Biodegradable and non-biodegradable substances
• Water pollution, water purification

Important Questions:

1. Food chain: Producer, consumer (primary, secondary, tertiary), decomposer example
2. 10% law: Energy transfer between trophic levels
3. Ozone layer: Location, function, causes of depletion, CFCs
4. 3R: Reduce, Reuse, Recycle with one example each
5. Biodegradable vs non-biodegradable: Examples and degradation time

Expected Questions:

• 1 very short answer (1 mark): What is 10% law?
• 1 short answer (2 marks): Ozone depletion causes
• 1 short answer (3 marks): Food chain with 4 trophic levels example
• 1 long answer (5 marks): Complete any NCERT exercise or waste management 3R explanation

14. Management of Natural Resources

Key Concepts:

• Water: Conservation, rainwater harvesting, water pollution, water purification
• Coal and petroleum: Formation, limited availability, conservation
• Food wastage and reduction
• Reforestation, conservation of flora and fauna

Important Questions:

1. Rainwater harvesting: Methods, advantages, components
2. Water purification: Steps (sedimentation, filtration, chlorination, boiling)
3. Coal formation: Carboniferous period, limited availability
4. Petroleum formation: Ancient organisms, refining, products
5. Reforestation: Definition, advantages, difference from deforestation

Expected Questions:

• 1 very short answer (1 mark): Name one water conservation method
• 1 short answer (2 marks): Rainwater harvesting advantages
• 1 short answer (3 marks): Coal formation process or petroleum products
• 1 long answer (5 marks): Complete NCERT exercise (2-3 questions) or water conservation essay

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CBSE 10th Science: Smart Study Strategy

Phase 1: Concept Building (April to July)

• Read NCERT textbook each chapter thoroughly (first reading)
• Solve all in-text questions (given within each chapter)
• Solve all end-of-chapter exercises (most important for exam)
• Make chapter notes with key concepts, formulas, and equations
• Create formula sheets for Physics (numerical) and Chemistry (reactions)

Phase 2: Intensive Practice (August to October)

• Solve previous 5 years’ CBSE board papers (understand question pattern)
• Solve NCERT Exemplar (higher-order thinking questions, 10-12 per chapter)
• Practise numerical problems daily (Physics: Ohm’s law, lenses, mirror formula; Chemistry: Chemical equations balancing)
• Make 1-page summary for each chapter (key points only)
• Weekly test: 20-25 questions from previous weeks’ topics

Phase 3: Final Polishing (November to February)

• Revise formula sheets daily (morning revision)
• Solve 3 full-length papers each week (3 hours, 80 marks)
• Focus on weak areas identified through practice
• Memorise common diagrams and their labels (Biology, Physics)
• Exam strategy: Attempt order, time allocation per section

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Chapter-Wise Weightage and Priority Order

High Priority (15+ marks each, focus first):

1. Carbon and Its Compounds (10-12 marks) - Organic chemistry, maximum questions
2. Electricity (8-10 marks) - Numerical problems, very scoring if concepts clear
3. Light - Reflection and Refraction (8-10 marks) - Diagrams carry full marks
4. Chemical Reactions and Equations (8-10 marks) - Balancing equations, reaction types
5. Life Processes (8-10 marks) - Diagrams (human eye, excretory system, photosynthesis)

Medium Priority (6-8 marks each):

6. Acids, Bases and Salts (6-8 marks) - pH, reactions, preparation
7. Metals and Non-metals (4-6 marks) - Properties, reactivity series
8. Control and Coordination (6-8 marks) - Nervous and hormonal control
9. Heredity and Evolution (8-10 marks) - Mendel’s laws, evolution
10. How do Organisms Reproduce? (6-8 marks) - Asexual vs sexual reproduction

Lower Priority (3-5 marks each - if time permits):

11. Sources of Energy (3-5 marks) - Conserve, environmental impact
12. Our Environment (3-5 marks) - 3R, ozone, food chain
13. Management of Natural Resources (3-5 marks) - Water, coal, petroleum

Priority Study Order (Recommended):

Week	Focus Areas	Reason
1-2	Carbon and Its Compounds + Electricity	Highest weightage, most questions in exam
3-4	Light - Reflection and Refraction + Chemical Reactions	Diagram questions + equation questions
5-6	Life Processes + Heredity and Evolution	Diagram-based + theory questions
7-8	Acids, Bases and Salts + Metals and Non-metals	Formula and concept-based
9-10	Remaining chapters (lower priority)	If time permits after high and medium priority

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What We Offer:

✅ Chapter-wise important questions exactly as per CBSE board exam pattern ✅ NCERT-based teaching - 80% of questions directly from NCERT ✅ Numerical practice sessions for Physics (Ohm’s law, lens/mirror formula, electricity calculations) ✅ Diagram practice workshops for Biology and Physics (labelling, neat diagrams) ✅ Chemistry reaction workshops (balancing equations, identifying reaction types) ✅ Weekly tests with detailed solution analysis (20-25 questions, 1 hour) ✅ Practical-based questions integration (as per CBSE increasing practical weightage) ✅ Error log maintenance and recurring mistake remediation ✅ Printed study material with chapter-wise important questions and notes ✅ Parent communication: Weekly test scores via WhatsApp, monthly progress reports

CBSE Science Batch Details:

Feature	Details
Batch Size	Max 30 students (personal attention for diagrams and numerical)
Teachers per Subject	2 (one for concepts/theory, one for numerical/diagrams)
Days per Week	3 days (Monday, Wednesday, Friday) or (Tuesday, Thursday, Saturday)
Hours per Batch	2 hours (1 hour theory + 1 hour practice/numerical)
Medium	English (primary), with Hindi support as needed
Batch Start	June 2026 (new academic year)
Admission	Interaction session + baseline assessment in Science

Our CBSE Science Students’ Results (2026):

• 94% of our CBSE Science students scored 80%+ in Class 10 boards
• 87% scored 90%+ in Science subject (highest distinction)
• 100% completed all NCERT textbook questions and exercises
• 95% appeared for NTSE Stage 1 (state level, foundation from Class 9)
• 85% won medals in Science Olympiad at school/state level
• Diagram accuracy: 90%+ students scored full marks (3/3 or 5/5 marks) in diagram questions
• Numerical accuracy: 85%+ students solved 80%+ numerical problems correctly

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CBSE Class 10 Science mastery comes from NCERT thoroughness + regular practice. Our program ensures students don’t just memorise but understand concepts, enabling them to solve any question variation in the board exam.

Want CBSE Science support for your child? Book a counselor meeting → | Explore our CBSE Science program → | View our CBSE Science results → | Visit our branches → /charoli/)