Science Class 9 Marks:
100
1. Give reason for the following
observations: 4
(a) An air cooler gives cool and
pleasant air during hot and dry summer afternoon.
(b) We can get the smell of perfume
sitting several metres
away.
2. What are the properties of a
suspension? 33. How can we obtain different gases from air? Explain in detail with diagram. 5
4. Write the molecular formulae of: 5
(i)
Sodium bicarbonate
(ii)
Aluminium chloride
(iii)
Potassium hydroxide
(iv)
Magnesium sulphate
(v)
Copper (I) oxide
5. Explain with examples (i) Atomic
number, (ii) Mass number, (iii) Isotopes and (iv) Isobars. Give any two uses of isotopes. 56. What would happen to the life of a cell if there were no Golgi apparatus? 3
7. Which cell organelles other than the nucleus have its own genetic material? 2
8. Name the different types of cells in xylem tissue? 2
9. What is the primary characteristic on which the first division of organisms is made? 1
10. Which phyla do these belong to: (1) Octopus (2) Starfish (3) Butterfly 3
11. Starting from a stationary position, Rahul paddles his bicycle to attain a velocity of 6 m s-1 in 30s. Then he applies brakes that the velocity of the bicycle comes down to 4 m 5-1 in the next 5 s. Calculate the acceleration of the bicycle in both the cases. 4
12. A car accelerates uniformly from 18km h-1 to 36 h-1 in 5 s. Calculate (i) the acceleration and (ii) the distance covered by the car in that time. 4
13. Write note on Conservation of Momentum. 2
14. State Newton’s three laws of motion. 3
15. What do you mean by buoyancy? 1
16. Relative density of silver is 10.8. The density of water is 103kg m-3.What is the density of silver in SI unit? 3
18. What is the kinetic energy of an object? Write an expression for the kinetic energy of an object. 2
19. What is power? Define 1 watt of power. 2
20. An electric bulb of 60 W is used for 6 h per day. Calculate the ‘units’ of energy consumed in one day by the bulb. 3
21. State the conditions for an echo to be heard? 2
22. Write two functions of stomata. 2
23. Explain the principles of prevention of diseases. 4
24. Explain nitrogen cycle. 5
25. Calculate the number of moles in 51g of NH3. (Atomic mass of Nitrogen is 14 u and
that of Hydrogen is 1 u). 3
26. Draw the atomic structure of the first five elements to show the electron distribution in the orbits. 5
27. What is Avogadro’s number? 1
28. Explain why: 4
(1) A gun recoils on firing?
(2) When a carpet is beaten with a stick, dust comes out of it?
29. What do you mean by Average Speed? 1
30. A truck and a car are running at same velocity. Which of these have less kinetic energy? Explain. 2
31. Give an example of electric energy converted into mechanical energy. 1
32. Differentiate between distance and displacement. 2
33. Explain with diagram a plant cell. 5
34. Name these: 3
a. The tissue that store fats in our body
b. The tissue with a fluid matrix.
c. The tissue present in our brain.
35. Which method is commonly used in improving cattle breeds and why? 2
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