CBSE Class 10 Science Important Questions 2026
Science is one of the highest-scoring subjects in the CBSE Class 10 Board Examination. Students who focus on important concepts, NCERT questions, and previous-year board questions can significantly improve their scores. In this article, we have compiled chapter-wise important questions and preparation tips to help students perform well in the CBSE Class 10 Science Board Exam 2026.
Why Are Important Questions Helpful?
Important questions help students:
- Understand frequently asked concepts.
- Improve confidence before examinations.
- Focus on high-weightage topics.
- Practice board-level questions effectively.
- Strengthen conceptual understanding.
Chapter 1: Chemical Reactions and Equations
Important Questions
- What is a chemical reaction? Explain with an example.
- State the law of conservation of mass.
- Differentiate between combination and decomposition reactions.
- What is oxidation and reduction?
- Explain corrosion and rancidity with suitable examples.
Practice balancing chemical equations regularly as it is frequently asked in board examinations.
Chapter 2: Acids, Bases and Salts
Important Questions
- Define acids and bases with examples.
- Explain the pH scale and its significance.
- Why does tooth decay occur when the pH in the mouth falls below 5.5?
- Describe the preparation of baking soda.
- Write the uses of bleaching powder.
Learn all chemical formulas, reactions, and industrial applications thoroughly.
Chapter 3: Metals and Non-Metals
Important Questions
- Differentiate between metals and non-metals.
- What is the reactivity series?
- Explain ionic bond formation.
- Describe the extraction of metals from ores.
- What is corrosion? How can it be prevented?
Chapter 4: Carbon and Its Compounds
Important Questions
- Explain covalent bonding.
- What are homologous series?
- Write the properties of ethanol and ethanoic acid.
- What is saponification?
- Explain the cleansing action of soap.
Board Tip
Organic chemistry questions are often concept-based. Focus on understanding rather than memorization.
Chapter 5: Life Processes
Important Questions
- Define nutrition and explain its types.
- Explain the human digestive system.
- Describe the process of respiration.
- Explain transportation in plants.
- Differentiate between arteries and veins.
Chapter 6: Control and Coordination
Important Questions
- What are neurons? Explain their structure.
- Describe the reflex action mechanism.
- Explain the role of hormones in plants.
- Differentiate between nervous and endocrine systems.
- Explain phototropism and geotropism.
Chapter 7: How Do Organisms Reproduce?
Important Questions
- Define reproduction and its importance.
- Differentiate between asexual and sexual reproduction.
- Explain binary fission with examples.
- Describe the reproductive system in humans.
- What are contraceptive methods?
Chapter 8: Heredity and Evolution
Important Questions
- What is heredity?
- Explain Mendel’s experiments.
- Define dominant and recessive traits.
- What is evolution?
- Explain natural selection.
Chapter 9: Light – Reflection and Refraction
Important Questions
- State the laws of reflection.
- Differentiate between real and virtual images.
- Explain refraction of light.
- What is refractive index?
- Draw ray diagrams for image formation by lenses.
Chapter 10: The Human Eye and the Colourful World
Important Questions
- Explain the structure of the human eye.
- What is accommodation?
- Differentiate between myopia and hypermetropia.
- Explain atmospheric refraction.
- Why is the sky blue?
Chapter 11: Electricity
Important Questions
- Define electric current and potential difference.
- State Ohm’s Law.
- Differentiate between series and parallel circuits.
- What factors affect resistance?
- Solve numerical problems based on electric power.
Board Tip
Memorize formulas and practice numerical questions daily.
Chapter 12: Magnetic Effects of Electric Current
Important Questions
- Explain the magnetic field around a conductor.
- State Fleming’s Left-Hand Rule.
- What is an electric motor?
- What is electromagnetic induction?
- Explain the working of a generator.
Chapter 13: Our Environment
Important Questions
- What is a food chain?
- Explain food webs.
- What are biodegradable substances?
- Discuss ozone layer depletion.
- Why is waste management important?
Chapter 14: Sustainable Management of Natural Resources
Important Questions
- What is sustainable development?
- Explain rainwater harvesting.
- Why is forest conservation important?
- Discuss water conservation methods.
- Explain the concept of the three Rs: Reduce, Reuse, Recycle.