10th Science Important 5 Mark Questions

Secure your top scores in the long-answer section by thoroughly practicing the 10th Science Important 5 Marks questions. This section heavily tests your descriptive knowledge, requiring a deep understanding of core scientific laws, chemical reactions, and biological diagrams across Physics, Chemistry, and Biology. This expert-curated guide brings you the most frequently repeated 5-mark questions, structured answers, and essential derivation steps to help you present your answers perfectly and score maximum marks in your upcoming board exams.

X SCIENCE - FIVE MARKS

IMPORTANT - FIVE MARKS QUESTIONS

1. i) State two necessary conditions for hearing an echo.
ii) What are two medical applications of echo?

2. i) Calculate the percentage of nitrogen atom in ammonia molecule.
ii) A is a silvery white metal. A reacts with O₂ at 800°C to form compound B. The alloy of A is used in making aircraft parts. Identify A and B.

3. i) Define: Co-efficient of linear expansion.
ii) The length of an aluminium rod at the temperature 303 K is 50m. What would be its increase in length when it is heated to 323 K? (The linear co-efficient of Aluminium is 23 × 10^-6 K^-1)

4. i) Distinguish between somatic gene therapy and germ line gene therapy.
ii) What are the various routes by which transmission of human immuno-deficiency virus takes place?

5. i) Give an example for each kind of solution given: a) gas in liquid b) solid in liquid.
ii) Calculate the pH value of 1.0 × 10^-4 molar solution of HNO₃.

6. List out the uses of echo.

7. i) How does leech respire?
ii) Why is vegetative propagation practiced for growing some types of plants?

8. How does fossilization occur in plants?

9. i) From the following clues identify the group number in the periodic table and write the names of any two elements of that group:
a. The atoms of this group have very stable electronic configuration
b. These elements are mostly unreactive.
ii) Why ethene is more reactive than ethane?

10. i) State whether the following statement is true or false, justify your answer:
According to Charles' law, at constant pressure, the temperature of the gas is inversely proportional to its volume.
ii) Fill in the blanks:
a) The temperature and heat are _______ quantities
b) _______ is the average kinetic energy of the molecules of a substance

11. i) Calculate the percentage of oxygen in Al₂(SO₄)₃ compound. (Mass number values are: Al - 27, O - 16, S - 32)
ii) Write the IUPAC name of the simplest ketone and give its molecular formula.

12. i) 3.5 litres of ethanol is present in 15 litres of aqueous solution of ethanol. Calculate volume percent of ethanol.
ii) Identify and write the type of following chemical reactions:
a) NH₄OH(aq) + CH₃COOH(aq) → CH₃COONH₄(aq) + H₂O(l)
b) ZnCO₃(s) →^Heat ZnO(s) + CO₂(g)

13. i) Electronegativity value of hydrogen is 2.1 and that of sodium is 1. Find out the nature of bonding present in the compound, when hydrogen combines with fluorine and hydrogen combines with sodium. (Electronegativity value of fluorine is 4).
ii) Applying IUPAC rules, derive the structural formula of the following compounds:
a) Pentanoic acid
b) 2-methyl-butan-2-ol

14. What is the importance of valves in the heart?

15. i) What are the hormones secreted by posterior lobe of the pituitary gland? Mention the tissues on which they exert their effect.
ii) What are allosomes?

16. i) Name the types of stem cells.
ii) What are the agents of soil erosion?

17. i) Differentiate systemic circulation and pulmonary circulation.
ii) Minerals in the plants are not lost during the falling of leaves. Give reason.

18. i) Draw the ray diagram of image formation in simple microscope.
ii) Find the position and write the nature and size of the image formed by a simple microscope.

19. i) Why do apples weigh more at the poles than at the equator?
ii) Differentiate convex lens and concave lens.

20. i) Keeping the temperature as constant, if a gas in a container is compressed to four times its initial pressure, the volume of gas changes from 20 cc (V₁ cc) to V₂ cc. Find the final volume V₂.
ii) Use the analogy to fill the blank:
1) Bats: Ultrasonic, Earth quake : _______
2) Whispering Gallery: Application of echo, Tracking a satellite : _______

21. i) Write any two properties of gamma radiation.
ii) What are control rods? Give an example.

22. i) Name the acid that renders aluminium passive. Give reason for this.
ii) Write any two characteristics of chemical equilibrium.

23. i) Analyse the given assertion and reason. Choose the correct option:
Assertion: The Relative Molecular Mass of Chlorine is 35.5 a.m.u.
Reason: The natural abundance of isotopes of chlorine is not equal.
a) A and R are correct, R explains A. b) A is correct, R is wrong.
c) A is wrong, R is correct. d) A and R are correct, R doesn't explain A.
ii) Distinguish between soaps and detergents.

24. How is the digestive system of rabbit suited for herbivorous mode of feeding?

25. What are the different phases of menstrual cycle? Indicate the changes in the ovary and uterus.

26.
i) Differentiate myelinated and non-myelinated nerve fibre.
ii) If we cross two different parents with the genotype of Tt × tt, what would be the genotypic ratio in its F₁ generation?

27.
i) State the applications of DNA fingerprinting technique.
ii) What is the role of fat in the cause of atherosclerosis?

28.
i) Calculate the mass of water required in grams to dissolve 10g of sucrose to produce the mass percentage of 10% solution.
ii) Which one of the following reactions is feasible? Give support to your answer:
a) 2NaCl + F₂ → 2NaF + Cl₂
b) 2NaF + Cl₂ → 2NaCl + F₂

29.
i) Use the analogy to fill the blank:
a) Opening a door: Moment of force, Opening a water tap: _______
b) Pushing a bus by a group of people: Like parallel forces, Tug of war : _______
ii) The power of a lens is -2D. Find the focal length of the lens.

30.
i) From the given figure, calculate the angle of reflection of sound.
ii) Nuclear fission of a uranium nucleus (U²³⁵) is given as follows: ₉₂U²³⁵ + ₀n¹ → X + Y + 3 ₀n¹ + Q (energy).

31.
i) a) Atoms of different elements having same number of _______ are called isotones.
b) The number of atoms present in a molecule is called its _______.
ii) What is rust? Write the chemical equation for the formation of rust.

32.
i) What happens when MgSO₄·7H₂O is heated? Write the appropriate equation.
ii) Understand the assertion statement and the reason given and choose the correct choice:
Assertion (A): Detergents are more effective cleansing agents than soaps in hard water.
Reason (R): Calcium and magnesium salts of detergents are water soluble.
a) A and R are correct, R explains A. b) A is correct, R is wrong.
c) A is wrong, R is correct. d) A and R are correct, R doesn't explain A.

33.
i) The mass percentage of carbon is 27.28% and the mass percentage of oxygen is 72.73%. Calculate the empirical formula and molecular mass of that compound.
ii) Copper pyrites is the prime ore of copper. It is concentrated by froth floatation method. Give the reason.

34.
i) Why are the rings of cartilages found in trachea of rabbit?
ii) Define reflex arc.

35. What are synthetic auxins? Give examples.

36.
i) How can menstrual hygiene be maintained during menstrual days?
ii) Name three improved characteristics of wheat that helped India to achieve high productivity.

37.
i) How is a cancer cell different from a normal cell?
ii) Why fossil fuels are to be conserved?

38.
i) Electric power lines in electrical posts hang very low in hot summer, why?
ii) An electric heater of resistance 5 Ω is connected to an electric source. If a current of 6 A flows through the heater, then find the amount of heat produced in 5 minutes.

39.
i) A force of 5 N applied on a body produces an acceleration of 5 cm s^-2. Calculate the mass of the body.
ii) An object of height 3 cm is placed at 10 cm from a convex lens which produces an image at 20 cm from its optical centre. Calculate the magnification and height of the image produced.

40. An organic compound 'A' is widely used as a preservative and has the molecular formula C₂H₄O₂. This compound reacts with ethanol to form a sweet smelling compound 'B'.
i) Identify the compounds 'A' and 'B'.
ii) Write the balanced chemical equation for the reaction between compound 'A' and ethanol to form compound 'B'.
iii) Name the chemical reaction.

41.
i) What are the reactants and products for both light and dark reactions?
ii) Differentiate voluntary actions from involuntary actions.

42. Draw and label the diagram of a typical angiospermic ovule and describe it.

43.
i) A pure tall plant (TT) is crossed with a pure dwarf plant (tt), what would be the F₁ and F₂ generations? Explain.
ii) Correct the false statements:
(a) The use and disuse theory of organs was postulated by Charles Darwin.
(b) Birds have evolved from mammals.

44. What are the effects of hybrid vigour in animals?

45.
i) What will be the impact of temperature and pressure while dissolving carbon dioxide in water?
ii) Does pure water conduct electricity? Justify your answer.

46.
i) How does a developing embryo get its nourishment inside the mother's body?
ii) Discuss the method of plant breeding for disease resistance.

47. Natural selection is a driving force for evolution — How?

48. Draw the structure of a dicot root and label the parts.

49. Compound A is a colourless liquid having burning taste. When the vapour of compound A is passed over heated copper at 573 K, it is dehydrogenated to acetaldehyde. What is compound 'A'? What is the role of copper in this chemical reaction? Write the balanced chemical equation of this reaction.

50.
i) Convert 80°F temperature into kelvin scale.
ii) Write any two advantages of LED TV over the normal TV.