CBSE Class 8 Science Practice Paper 2026 with Answer Key (Set 3) – Ultimate Exam Preparation Guide

Introduction

Preparing for the CBSE Class 8 Science exam becomes much easier when students practice with well-designed question papers that follow the latest exam pattern. The CBSE Class 8 Science Practice Paper 2026 with Answer Key (Set 3) on a2zly.com has been created to help students strengthen their concepts and familiarize themselves with the CBSE Class 8 Science Practice Paper 2026, improve answer-writing skills, and understand how questions may appear in the final examination.

This practice paper is carefully structured according to the CBSE syllabus and NCERT guidelines, covering important chapters. By solving this paper, students can evaluate their preparation level, identify weak areas, and build confidence before their exams.

Practicing with the CBSE Class 8 Science Practice Paper 2026 will also aid students in becoming adept at handling different question formats and enhance their problem-solving abilities.

By using the CBSE Class 8 Science Practice Paper 2026, students will learn how to manage their study time effectively, ensuring they cover all necessary topics before the exam.

The included detailed answer key allows students to check their responses instantly and learn the correct way to present answers in the examination. Whether you are revising the syllabus or testing your knowledge through self-assessment, this practice paper from a2zly.com will serve as an effective study resource for achieving better results in the CBSE Class 8 Science Exam 2026.

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MODEL QUESTION PAPER – 2026

Subject: Science          Class: VIII             Maximum Marks: 60           Time: 2½ Hours SET 3

GENERAL INSTRUCTIONS

1. All questions are compulsory. Internal choices are provided in some questions.

2. Section A contains 10 MCQs and 2 Assertion–Reason questions of 1 mark each.

3. Section B contains 6 questions of 2 marks each.

4. Section C contains 6 questions of 3 marks each.

5. Section D contains 2 case-based questions of 4 marks each.

6. Section E contains 2 long answer questions of 5 marks each.

7. Draw neat and properly labelled diagrams wherever required.

SECTION – A (1 × 12 = 12 marks)

(Multiple Choice Questions)

Q1. What happens to air when it gets heated? (a) It contracts and becomes heavier (b) It expands and becomes lighter (c) It remains unchanged (d) It turns into water vapour only

Answer: (b) It expands and becomes lighter

Explanation: Heating increases kinetic energy of air particles → they move farther apart → volume expands → density decreases → air becomes lighter and rises (convection).

Q2. Which of the following statements is correct about solids? (a) Solids have no fixed shape and no fixed volume (b) Solids have a fixed shape and fixed volume (c) Solids can be compressed easily (d) Solids flow from one place to another

Answer: (b) Solids have a fixed shape and fixed volume

Explanation: In solids, particles are closely packed with strong intermolecular forces → fixed positions → definite shape and volume. They cannot be compressed easily or flow.

Q3. Which of the following substances is a compound? (a) Hydrogen (b) Gold (c) Carbon dioxide (d) Iron

Answer: (c) Carbon dioxide

Explanation: Compound = two or more elements chemically combined (CO₂ = carbon + oxygen). Hydrogen, gold, iron are elements (pure substances with one type of atom).

Q4. Which of the following factors affects the rate of evaporation? (a) Temperature only (b) Surface area only (c) Wind speed only (d) Temperature, surface area and wind speed

Answer: (d) Temperature, surface area and wind speed

Explanation: Rate of evaporation increases with: higher temperature (more kinetic energy), larger surface area (more particles escape), wind (removes humid air above surface).

Q5. The most widely used calendar in the world is the: (a) Saka calendar (b) Lunar calendar (c) Hijri calendar (d) Gregorian calendar

Answer: (d) Gregorian calendar

Explanation: Gregorian calendar (introduced 1582) is the international civil calendar (365 days + leap year adjustment).

Q6. Which of the following is an example of commensalism? (a) A tapeworm living in the human intestine (b) Cattle egret feeding on insects near grazing cattle (c) A mosquito sucking human blood (d) Cuscuta growing on a host plant

Answer: (b) Cattle egret feeding on insects near grazing cattle

Explanation: Commensalism: one benefits (+), other unaffected (0). Egret gets food; cattle unaffected. Others are parasitism (-/+).

Q7. Which of the following conditions is most suitable for the formation of a cyclone? (a) Very low temperature over land (b) Warm ocean water and low air pressure (c) Heavy snowfall in mountains (d) High air pressure over the sea

Answer: (b) Warm ocean water and low air pressure

Explanation: Cyclones form over warm ocean water (>26–27°C) → evaporation → rising moist air → low pressure centre → winds spiral in.

Q8. Anamika filled a balloon with air… expanded in sunlight… shrank in cooler room. Which property of gases is demonstrated? (a) Gases are incompressible (b) Gases have a fixed shape (c) Gases expand on heating (d) Gases have strong intermolecular forces

Answer: (c) Gases expand on heating

Explanation: Heating → particles gain kinetic energy → move farther → volume increases (balloon expands). Cooling → opposite.

Q9. What type of image is formed by a concave mirror when the object is placed between the pole and the focus? (a) Real and inverted (b) Real and erect (c) Virtual and erect (d) Virtual and inverted

Answer: (c) Virtual and erect

Explanation: For concave mirror, object between pole and focus → virtual, erect, magnified image (used in makeup/shaving mirrors).

Q10. Which of the following is an example of mutualism? (a) A tapeworm… (b) A mosquito… (c) Lichen (algae and fungus living together) (d) A tick…

Answer: (c) Lichen (algae and fungus living together)

Explanation: Mutualism: both benefit. Algae provides food (photosynthesis); fungus provides shelter, water, minerals.

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

Q11.

Assertion (A): Farmers add manure and fertilizers to the soil.
Reason (R): Crops absorb nutrients from the soil during growth.

Answer: (a) Both A and R are true and R is the correct explanation of A.

Explanation:
As crops grow, they use nutrients from the soil. Manure and fertilizers replenish these nutrients, maintaining soil fertility.

Q12.

Assertion (A): Weeds should be removed from crop fields.
Reason (R): Weeds compete with crops for nutrients, water, light, and space.

Answer: (a) Both A and R are true and R is the correct explanation of A.

Explanation:
Weeds grow along with crops and compete for essential resources. Removing them ensures better crop growth and higher yield.

Utilizing the CBSE Class 8 Science Practice Paper 2026 as part of your study routine can significantly boost your confidence and readiness.

SECTION – B (2 × 6 = 12 marks)

Short Answer Questions – I (2 × 6 = 12 marks)

Q13. Why do camels have broad and flat feet?

Answer: Camels have broad and flat feet to reduce pressure on sand and prevent sinking.

Explanation: Pressure = Force / Area. Broad feet increase area → decrease pressure → camel walks easily on loose sand without sinking.

Q14. Why do gases have neither fixed shape nor fixed volume?

Answer: Gases have neither fixed shape nor fixed volume because their particles are far apart with very weak intermolecular forces.

Explanation: Particles move freely in all directions → fill entire container (take its shape) and expand/compress easily → no fixed volume.

Q15. What are alloys? Name the alloy formed by copper and zinc.

Answer: Alloys are homogeneous mixtures of two or more metals (or metal + non-metal) prepared by melting and mixing.

Example: Brass (copper + zinc).

Q16. A stone sculpture has a mass of 300 g and a volume of 120 cm³. Calculate its density. State whether it will float or sink in water.

Answer: Density = Mass / Volume = 300 g / 120 cm³ = 2.5 g/cm³

It will sink in water.

Reason: Density (2.5 g/cm³) > density of water (1 g/cm³) → weight > buoyant force.

Q17. What is dispersion of light? Name the instrument used to obtain the spectrum of white light.

Answer: Dispersion of light: Splitting of white light into seven colours (VIBGYOR) when passed through a prism (due to different wavelengths bending differently).

Instrument: Prism (or spectrometer).

Q18. Define the term food chain. Arrange the following organisms in the correct order of a food chain: Grasshopper, Snake, Eagle, Grass, Frog.

Answer: Food chain: Linear sequence showing transfer of food/energy from one organism to another in an ecosystem (producer → consumer).

Correct order: Grass → Grasshopper → Frog → Snake → Eagle

SECTION – C (3 × 6 = 18 marks)

Short Answer Questions – II (3 × 6 = 18 marks)

Q19. State any three characteristics of particles of matter.

Answer: (From NCERT particulate nature of matter)

1. Particles of matter are very tiny (extremely small, not visible even under ordinary microscope).
2. There are spaces between particles of matter (interparticle spaces).
3. Particles of matter are continuously moving (kinetic energy increases with temperature). (Also: Particles attract each other with interparticle forces.)

Q20. Pressure is defined as Force/Area. Comment on how pressure affects density.

Answer: Pressure and density are related, especially in fluids/gases. Increasing pressure usually increases density.

Explanation: Higher pressure compresses particles closer together → decreases volume for same mass → density (mass/volume) increases. Example: In gases (compressible), high pressure → higher density (e.g., compressed air). In liquids (less compressible), effect is small but present.

Q21. Name the type of mirror that can burn paper by concentrating sunlight. Mention two practical uses of this mirror in daily life.

Answer: Concave mirror (converging mirror).

Practical uses:

1. Used in solar cookers / solar furnaces to concentrate sunlight and produce heat.
2. Used by dentists/doctors as head mirrors to focus light into mouth/ear.

Q22. What is a satellite? Differentiate between natural and artificial satellites with one example each.

Answer: Satellite: Any object that revolves around a planet (or other body) in a fixed orbit.

Difference:

Feature	Natural Satellite	Artificial Satellite
Origin	Formed naturally	Man-made
Example	Moon (Earth’s natural satellite)	INSAT or Chandrayaan satellites

Q23. Differentiate between biosphere and geosphere. Mention one importance of geodiversity.

Answer:

Feature	Biosphere	Geosphere
Definition	Part of Earth with living organisms (plants, animals, microbes) and their interactions	Solid part of Earth (rocks, minerals, crust, mantle, core)
Includes	All ecosystems, life processes	Lithosphere (land), no direct life

Importance of geodiversity: Provides variety of minerals, rocks, soils → supports different habitats, resources (ores, fuels), and geological processes essential for life.

Q24. What will happen if all the decomposers are removed from an ecosystem? Explain.

Answer: If decomposers (bacteria, fungi) are removed:

• Dead plants/animals and waste will accumulate → no recycling of nutrients.
• Soil will become nutrient-deficient → plants cannot grow properly (producers suffer).
• Food chain/web collapses → consumers (herbivores, carnivores) starve.
• Ecosystem balance disrupted → biodiversity loss, eventual collapse.

SECTION – D (4 × 2 = 8 marks)

Case-Based Questions (4 × 2 = 8 marks)

Q25. Anita took a strip of paper and held it close to her lips so that it hung downward. She then blew air horizontally over the top surface of the paper strip. Based on this observation, answer the following questions:

(a) What happens to the paper strip?
(b) What change occurs in air pressure above the strip?
(c) Explain the reason behind this observation.

Answer: (a) The paper strip rises upward / moves up.

(b) Air pressure above the strip decreases (lower pressure region created).

(c) Bernoulli’s principle: Fast-moving air (blown over top) has lower pressure than still/slower air below. Higher pressure below pushes paper upward.

Q26. During a space activity in her science class, Neha learned that the Moon’s orbit around the Earth is slightly tilted with respect to the Earth’s orbit around the Sun. Her teacher explained that this tilt affects the occurrence of eclipses. Based on this information, answer the following questions:

(a) How does the tilt of the Moon’s orbit affect the occurrence of eclipses?
(b) Why are eclipses rare events?
(c) Which type of eclipse occurs when the Moon completely enters the Earth’s shadow?

Answer: (a) Tilt (~5°) means Sun, Earth, Moon rarely align perfectly → eclipses occur only when Moon is at nodes (intersection points).

(b) Eclipses are rare because perfect alignment is infrequent due to tilt + orbital positions.

(c) Lunar eclipse (total when Moon fully in Earth’s umbra).

SECTION – E (5 × 2 = 10 marks)

Long Answer Questions (5 × 2 = 10 marks)

Q27. When magnesium ribbon is burned in air, a white powder is formed. a) Name the compound formed. b) How can you confirm the presence of this compound? c) Write the word equation for the reaction.

Answer:

a) Magnesium oxide (MgO)

b) Test/Confirmation: Dissolve white powder in water → forms magnesium hydroxide (basic solution) → turns red litmus blue.

c) Word equation: Magnesium + Oxygen → Magnesium oxide

Q28.

A. A river flowing through a town has been heavily polluted due to the disposal of industrial waste. Discuss the possible impacts… on the local ecosystem and human health.

B. List any three ways in which individuals can reduce environmental pollution in their daily lives.

Answer:

A.

• Ecosystem impacts: Toxic chemicals kill fish/aquatic life → food chain disruption → loss of biodiversity. Algal blooms (eutrophication) → oxygen depletion → dead zones. Plants/animals poisoned → long-term habitat damage.
• Human health impacts: Contaminated drinking water → diseases (cancer, neurological issues, skin problems). Bioaccumulation in fish → health risks on consumption. Respiratory/skin issues from polluted air/water contact.

B. Three ways individuals can reduce pollution:

1. Reduce, reuse, recycle waste (less landfill, less burning).
2. Use public transport/cycle/walk instead of private vehicles (reduce air pollution).
3. Save electricity/water, avoid single-use plastics (lower resource use and waste).

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Conclusion

Regular practice is the key to scoring well in exams. By attempting the CBSE Class 8 Science Practice Paper 2026 with Answer Key (Set 3), students can become familiar with the exam format, improve time management, and strengthen their understanding of important scientific concepts.

Students are encouraged to first attempt the paper independently and then verify their answers using the provided answer key. This method not only helps in self-evaluation but also improves conceptual clarity and confidence.

For more CBSE study materials, practice papers, model question papers, and exam preparation resources, keep visiting a2zly.com. Our goal is to provide students with high-quality, easy-to-understand learning content that supports their academic success.

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For optimal results, integrate the CBSE Class 8 Science Practice Paper 2026 into your study sessions and watch your performance improve.

Remember, consistent practice with the CBSE Class 8 Science Practice Paper 2026 will yield the best outcomes on exam day.