CBSE Class 9 Science Revision Worksheet

Q1.Force can change

a) Velocity of a body b) Direction of a velocity

c) Magnitude of a velocity d) All the above

Q2. SI unit of force is

a) Newton

b) Dyne

c) Joule

d) N-m

Q3.Rate of change of Momentum is known as

a)Work b) Force

c) Impulse d) Energy

Q4.Momentum of a body increases from 20kgm/s to 40kgm/s in 5 seconds, then the force applied is

A) 4 N b)-4 N

c)12 N d) -12 N

Q5.If no external force acts on a body, then the quantity which remains conserved is

A) Momentum b)Work

c) Energy d) Mass

Q6.When a bullet is fired from a gun, it recoils .This is due to

a) Conservation of Energy

b) Mass

c) Momentum

D) None

Q7.When a body slides over the other body, then friction between them is known as

a) Limiting friction

b) Rolling friction

c) Sliding friction

d) Static friction

Q8.The friction in the case of bodies that moves rollers is known as

a) Rolling friction b) Sliding friction

b) Static friction d) Limiting friction

Q9. Which of the following measures are taken to reduces friction

a) Polishing

b) Streamlining

c) Using ball bearing

d) All the above

Q10.Which is not a unit of pressure

a) Pascal b) Atmosphere

b) Bar d) Newton

Q11. A mug filled with water appears to be lighter when lifted inside water, due to

a) Conservation of Momentum b) Archimedes principle c) Newton’s law d) None

Q12. A block of relative density 5 is put in a liquid of density 2000kg/ms3, it will

a) Sink b) Float c) Cannot say d) Insufficient data

Q13. Velocity of a particle increases from 10m/s to 15m/s after travelling a distance of 5m its acceleration is

a) 12.5m/s2 b) 125 m/s2 c) 1.25m/s2 d) 0.1m/s2

Q14.A particle is moving in a circular path of radius r the displacement after half a circle would be

a) Zero b) 2r c) 2πr d) π

Q15. In uniform circular motion velocity of particle is

a) Constant b) Variable in magnitude c) Variable in direction d) Both

Q16. Area under velocity – time gives

a) Displacement b) Acceleration c) Time d) Velocity

Q17. Suppose you push a wall then reaction force to this force is

a) The force applied by the wall b) Weight of the wall c) Weight of your body d) None

Q18. A particle travels 100 meters after starting from rest in 10 seconds. Its acceleration is

a) 2m/s² b) 4m/s² c) 1m/s² d) 20m/s²

Q18. A particle travels with the speed of 18km/h its speed is m/s

a) 5m/s b) 50m/s c) 64.8m/s d) 6.48m/s

Q19. Displacement-time graph of a uniformly accelerated motion is

a) Parabola b) Straight line c) An inclined line d) None

Q20. A body is thrown vertically upward with velocity U1 the greatest height to which it will rise is

a) U/g b) U2/2g c) U2/g d) U/2g

Sub: Chemistry Class: 9th Worksheet no: 2

Multiple Choice Questions

Q1.Colour of copper sulphate crystal is:

c) Light blue b) Light green

c) Light brown d) light yellow

Q2.When liquid air is heated then out of argon, nitrogen and oxygen:

e) Nitrogen evaporates first then argon.

f) Oxygen evaporates first then argon.

g) Argon evaporates first then oxygen.

h) Nitrogen evaporates first then oxygen.

Q3.Carbon disulphide at room temperature is a:

a) Coloured gas b) Colourless gas

c) Colourless liquid d) Coloured liquid

Q4. When we start heating a mixture of sulphur powder and iron fillings, the first thing we would observe is that:

A) Iron fillings start melting b) Sulphur starts melting

c) Mixture becomes red hot d) Mixture evaporate

Q5.Flame should not be brought near carbon disulphide while working with it because carbon disulphide:

A) Is supporter of combustion b)Dissolve sulphur

c) is highly inflammable d) is highly non-inflammable.

Q6.The correct observation when you mix barium chloride solution with sodium sulphate solution is that:

a) A white precipitate is formed after some time.

b) A yellow precipitate is formed after some time.

c) A white precipitate is formed instantaneously.

D) Ayellow precipitate is formed instantaneously.

Q7.The property of flow is unique to fluids which one of the following is correct?

e) Only gases behave like fluids.

f) Gases solids behave like fluids

g) Gas and liquids behave like fluids.

h) Only liquids are fluids.

Q8.Large amount of a gas can be put into a small metallic cylinder due to the property of gas known as:

b) Evaporation b) compressibility

d) Sublimation d) Solidification

Q9.Gases can best be liquefied by:

e) Increasing pressure

f) Decreasing temperature

g) Increasing pressure and decreasing temperature

h) Decreasing pressure

Q10.The quantity of heat (in joules) required to convert one kilogram of a liquid at its boiling point at an atmospheric pressure is called:

c) Specific heat b) Heat capacity

d) Latent heat of melting d) Latent heat of vaporization

Q11. Which of the following is not a compound

b) Sugar b) Sand c) Glucose d) Silica

Q12. Which of the following is an example of colloidal solution?

b) Blood b) Dust c) Sea water d) Tincture of Iodine

Q13. The light is …………. On passing light through a colloidal solution.

b) Absorbed b) Reflected c) Ink d) soil

Q14.Which of the following is a homogeneous mixture?

b) Soda water b) Milk c) Ink d) Soil

Q15. Sulphur is soluble in:

b) Water b) Ethanol c) carbon disulphide d) Benzene

Q16. Which of the following is sublimate?

b) Iodine b) Oxalic acid c) Wax d) Sand

Q17. Which of the following is not heterogeneous mixture?

b) Soil b) Blood c) Dirt d) Saline water

Q18. Which gas is present in aerated soft drinks?

b) Nitrogen b) Carbon dioxide c) Carbon monoxide d) Hydrogen

Q18.Which of the following is not Metalloid?

b) Boron b) Silicon c) Copper d) Germanium

Q19. Which of the following is an Emulsion?

b) Butter b) Milk c) Curd d) Smoke

Q20. In a foam, which of the following is a dispersed phase?

b) Solid b) Liquid c) Gas d) none of these

Q21. Which of the following is not a gel?

a) Butter b) Cheese c) Curd d) Ink

Q22. Which of the following is a binary Mixture?

a) Air b)Soft Drinks c) Steel d) Saline Solution

Q23. Alloy is a mixture of:

a) Solid and Liquid b) Liquid and Solid c) Solid and Solid d ) Liquid and gas

Q24. Which of the following is most malleable Metal?

a) Gold b) Silver c)Aluminum d)Copper

Q25. Amalgam is a mixture of a metal and:

a) Water b) Alcohol c) Mercury d) Benzene

Worksheet for class 9th Biology

Q1. To prepare a temporary mount of onion peel, which of the following stain is used?

(a) Safranin (b) Methylene blue

(c) Iodine (d) None of the above

Q2. Cells are focused in microscope first in:

(a) 100X (b) 40X

(C) 10X (D) None of the above

Q3. While observing a mount of onion peel under a microscope, cytoplasm is seen:

(a) Inside the nucleus (b)Inside the cell wall but outside nucleus

(c) outside the cell wall (d) not seen at all

Q4. The plant cell excluding cell wall is known as:

(a) Protoplasm (b) Protoplast

(c) Cytoplasm (d) None of the above

Q5. The membrane surrounding the vacuole of a plant cell is called:

(a) Plasma membrane (b) cell wall

(c) Tonoplast (d) nuclear membrane

Q6. When a cell is mounted in glycerin:

(a) Endosmosis takes place (b) exosmosis takes place

(c) Neither exosmosis nor endosmosis takes place

(d) None of the above

Q7. Given blow are four operations for preparing a temporary mount of human cheek cells:

(i) Taking scraping from inner side of the cheek and spreading it on a clean slide.

(ii) Putting a drop of glycerin on the material.

(iii) Adding two or three drops of methylene blue

(iv) Rinsing the mount with fresh water and disinfectant solution.

The correct common to both plant and animal cells are :

(a) i – ii – iii – iv (b) iv – i – iii – ii

(c) iv – I – ii – iii (d) i – iii – ii – iv

Q8. Which one of the following cell constituents cannot be seen while observing a human cheek cell?

(a) Nucleus (b) cell wall

(c) Cytoplasm (d) none of the above

Q9. Which of the following statement is false?

(a) Definite shape of cell is seen in animals. (b) Plant cell have cell wall.

(c) Definite shape of cell wall. (d) Animal cell do not have cell wall.

Q10. Cheek cells:

(a) Have large intercellular space (b) no inters cellular space

(c) Lignified space (d) space filled with pectin.

Q11. Amoeba acquires its food through a process, termed as

(a) Exocytosis (b) endocytosis

(c) Plasmolysis (d) exocytosis and endocytosis

Q12. A cell wall swells up if:

(a) The concentration of water molecule in the cell is higher than the constration of water molecules in surrounding medium.

(b) The concentration of water molecules in surrounding medium is higher than water molecule concentration in the cell.

(c) The concentration of water molecule is same in the cell and in the surrounding medium.

(d) Concentration of water molecule does not matter.

Q13. Which of the following are covered by a single membrane?

(a) Mitochondria (b) vacuole

(c) Lysosome (d) plastids

Q14. Starch solution gives blue colour with iodine solution. What will happen if the blue colour starch solution is boiled?

(a) Blue colour disappears (b) a brick red colour appears

(c) No change (d) blue colour becomes dark.

Q15. Which food sample you will select to test the presence of starch:

(a) Grape (b) coconut

(c) Gram seed (d) potato

Q16. Iodine gives blue black colour with:

(a) Protein (b) oil

(c) Starch (d) sucrose

Q17. Metanil yellow, an adulterant used in arhar dal is basically

(a) An acid (b) a detergent

(c) A die (d) none of the above

Q18. Cover slip should be gently placed on the slide to avoid:

(a) Crushing of the material (b) entry of air bubbles

(c) Avoid oozing of stain (d) breaking, as it is made of glass.

Q19. Adulterant arhar dal is plain yellow in colour due to

(a) Turmeric (b) sulphur powder

(c) Metanil yellow (d) chrome yellow.

Q20. Some characteristics of onion peel cells are:

(a) Cell wall is present (b) only one nucleus present

(c) Intercellular spaces are not there (d) all of the above.

Biology : Improvement of food resources

Q1 State and explain law of conservation of momentum.

Q2 Give reasons:

(1) On applying sudden breaks driver gets a forward jerk.

(2) A fielder lowers his hands while catching a ball.

Q3 Draw the graph for the following cases:

(1) Velocity time graph for body undergoing retardation.

(2) Distance time graph for a body at rest.

Q4 An object of mass 2kg moving with a velocity of 5m/s collides and sticks to a stationary wooden block of mass 5kg. They both move off together. Calculate the speed of the combined object.

Q5 Calculate the momentum of object of mass 5kg moving at a speed of 20km/hr.

Q6 Differentiate between homogeneous and heterogeneous mixture.

Q6 Define compound and give its characteristics.

Q7 Define evaporation and explain how temperature and surface area affect the rate of evaporation.

Q8 What is an aqueous solution? Give two examples.

Q9 A solution is formed by dissolving 50 gm of salt in 100 gm of water. Find the concentrationof solution in terms of mass percentage of solution.

Q10 What are pure substances? Give two examples.

Q11 What are pests? How do they attack our crops?

Q12 Differentiate between manures and fertilizers.

Q13 Write a short note on composite fish culture.

Q14 Name two indigenous and two exotic breeds of cow.

Q15 How can you say that an animal in zoo has fallen sick?

Solve the Numerical :

Q.1 Derive the equation for velocity-time relationship (v = u +at) by graphical method

Q.2. A sprinter in a 100m race covers 4m in the first second, 30m in the next 4s, 52m In another 4s and finishes the race in 10s. Calculate
a) Average velocity
b) In which time interval, is the average velocity attained by the sprinter maximum?
c) Plot the distance- time graph for the motion of sprinter.

Q.3. A train starting from rest, picks up a speed of 20m/s in 200s. It continues to move at Same speed for next 500s. It is then brought to rest in the next 100s.
a) Plot a speed time graph.
b) Calculate the rate of uniform acceleration
c) Calculate the rate of uniform retardation
d) Calculate the distance covered by the train during retardation.
e) Calculate the average speed during retardation.

Q.4. An object P is moving with a constant velocity for 5 minutes. Another object Q is moving with changing velocity for 5 mins. Out of the two objects, which one has acceleration?

Q.5. Draw the graph for the following cases

a) A ball thrown vertically upwards and returning back to the hands of the returner.
b) A body decelerating to a constant speed and accelerating.

Q.6. What does the slope of a displacement-time graph represents? Can displacement-time sketch Be parallel to the displacement axis? Give reason for your answer.

Q.7. What can we conclude about motion of a body depicted by the following velocitytime Graphs?

BIOLOGY:

Visit to any dairy farm to understand the practice of dairy farming. Involvement of animals of different breeds. Understanding technique of collection, storage, transport of dairy products. Prepare a project report on all these activities. You can paste colorful pictures, diagrams. It should be at least 10 page reports.

CHEMISTRY:

ANSWER THE FOLLWING QUESTIONS:

1. State characteristic property of (a) Solids (b) Liquids(c) Gases

2. Why is a solid not compressible? Why?

3. Give an example of compressed gas used at home.

4. Why is a solid not compressible?

5. Give reason for saying wood is a solid.

6. Why do gases exert pressure?

7. Gases are highly compressible whereas solids and liquids cannot be compressed. Why?

8. What is the general name of:
(a) Rigid form of matter and (b) Fluid form of matter.

9. Name two gases which are supplied in compressed form in homes and hospitals.

10. Liquids have fixed volume but no fixed shape. Why?

11. An inflated balloon collapses when pricked. Name the property of gases exhibited by this.

12. With the help of an experiment, how will you separate naphthalene a and sodium chloride?

13. Describe the scales of meaning temperature and pressure.

14. Define diffusion. Explain the effect of change of temperature on diffusion.

15. Solids are generally rigid. What do you say about a rubber band which changes its shape when stretched? Is it solid?

16. Write the name of the process of the following state change.
(a) Solid to liquid
(b) Liquid to solid
(c) Liquid to gas
(d) Gas to liquid
(e) Solid to gas
(f) Gas to solid

17. Which property of matter is helpful in survival of aquatic plants and animals?

18. What do you mean by?
(a) Latent heat of fusion
(b) Latent heat of vaporization

19. Differentiate between a gas and vapors.

20. Why does food cook faster in a pressure cooker?

21. Iron ball is solid and water is a liquid. How do two differ with respect to their shape, size, compressibility and diffusion?

22. Name the two main factors responsible for the difference in the three states of matter.

Section – A : Physics

1) Find the relation between momentum and kinetic energy. What will be the percentage change in kinetic energy if the momentum is doubled?

2) Illustrate the law of coservation of energy by discussing the energy changes which occur when we draw a pendulum both to one side and allow it to oscillate. Why does the bob eventually come to rest? What happens to its energy eventually? Is it a violation of law of conservation of energy?

3) A man weighing 40kg carries a box weighing 20 kg to the top of a building 15 m high in 25
seconds. Calculate the power.

4) A man fires a shot and hears an echo from a cliff after 2 sec. He walks 85m towards the cliff and the echo of a second shot is now heard after 1.4 sec. What is the velocity of sound and how far was the man from the cliff when he first heard the echo?

5) On what factors does the upthrust depend?

6) A block of wood in water with 3/4rd of its volume submerged. What will be the fraction of its volume submerged in liquid of relative density 0.8?

7) A wooden block floats is glycerine in such a way that its 2/5th volume remains above surface. If relative density of wood is 0.78. Calculate the relative density of glycerine.

8) The global climate has always fluctuated millon of year ago ,some part of the world that are now quite warm ,were covered with ice and over recent centuries , average temperature have risen and fallen in cycle what is new however is that current and future climate change will be caused not just by natural event but also by activities of human being. Suggest 3 simple ways to help save the climate of our planet.

Section – B : Chemistry

1. What are polyatomic ions? Give examples.

2. a) Calculate the formula unit mass of Na₂CO₃.10H₂O and K₂CO₃.
b) Calculate the molecular mass of C₂H₅OH and H₂SO₄

3. What is the mass of
a) 0.2 mole of oxygen atoms?
b) 10 mol of Na₂SO₃
c) 1.5 mol of Na⁺ ions.
d) 4 mol of Aluminium atoms (atomic mass of Al = 27)

4. What are isotopes ? Give one example.

5. The atomic number of Al and Cl are 13 and 17 respectively. What will be the number of electrons in Al3+ and Cl- ?

6. Write the conclusions and shortcomings of Rutherford’s model of an atom.

7. VALUE BASED QUESTION:

Rutherford’s atomic model was a reasonably good model of structure of atom based on the famous particle scattering experiment. However it was modified by Neil Bhor and later on by others. The resulting improvements in the understanding of atomic structure have contributed to further scientific advancement. There are many examples in scientific field when original contributers happily accept modifications in their ideas.

Answer the following questions based on the above information:

a) Name the scientific values associated with the above anecdotes.

b) In what way such a personal attribute is likely to help you?

Section – C : Biology

Chapters - Biological Diversity, Health & Diseases, Our Environment (Biogeochemical Cycles, Greenhouse Effect) :

1. What is evolution? How is algae different from fungi? Draw diagram of any one member of Protista.

2. How are Pteridophytes different from Bryophytes? Write any four differences between angiosperms and gymnosperms.

3. Write the differences (any four) between the following groups
a) poriferans and coelenterates
b) molluscs and arthropods
c) flatworms and roundworms
d) aves and mammals

4. Explain the different means by which infectious diseases spread in the environment? List the preventive measures of such diseases.

5. Justify giving reasons why it is difficult to make antiviral medicines than antibacterial medicines.

6. Explain the different processes involved in oxygen and water cycle operating in nature.

7. Represent schematically the carbon cycle and nitrogen cycle operating in the biosphere. How is greenhouse effect caused?

8. Value Based Question :

Government officials often go from one house to another every year and request people to take their infants to the Pulse Polio booths to administer polio drops to them. However in a particular area few infants were not taken for polio drops.

Answer the following questions;

a) Why does the government take active part in administering polio drops to infants?

b) What values are being ignored by people who do not take their infants to the Pulse Polio booths?

c) Government officials go from house to house for promoting polio drops vaccination. Besides doing their office duty, which values are promoted through their actions?

Section – A : Physics

1) To accelerate an object to a rate of 2m/s2, 10 N force is required. Find the mass of object.

2) If 1000 N force is required to accelerate an object to the rate of 5m/s2, what will be the weight of the object?

3) Differentiate between mass and weight?

4) A scooter is moving with a velocity of 20m/s when brakes are applied. The mass of the scooter and the rider is 180Kg. The constant force applied by the brakes is 500N.
a) How long should the brakes be applied to make the scooter come to a halt?
b) How far does the scooter travel before it comes to rest?

5) State Newton’s third law of motion and how does it explain the walking of man on the ground?

6) When a carpet is beaten with a stick, dust comes out of it. Explain

7) Why is it advised to tie any luggage kept on the roof of a bus with a rope?

Section – B : Chemistry

1. a) Convert the following temperatures to Celsius scale
i) 293 K ii) 470 K

b) Convert the following temperatures to Kelvin scale.
i) 250 C ii) 1370 C

2. Define sublimation. Give three examples of substances which undergo sublimation.

3. Differentiate between compounds and mixtures.

4. Write four characteristics of each of the following:

a) True solution b) Colloids c) Suspension

5. A solution contains 5 ml of alcohol mixed with 75 ml of water. Calculate the concentration of the solution in terms of volume percent.

Section – C : Biology

1. Name one site of occurrence of the following tissues in a living plant body?
a. Cambium b. Xylem c. Chlorenchyma

2. Mention the distinguishing feature of parenchyma, collenchyma and sclerenchyma tissue/cell.

3. Sieve tube cells of phloem tissue do not possess nuclei in mature state, still they remain alive. Give reason.

4. Write down any three differences between smooth, striated and cardiac muscles.

5. Enumerate the factors affecting stored grains and describe their preventive measures.

6. On visiting a nearby Cattle yard, a student found three different cross breeds of cows. They are Karan Fries, Frieswal & Karan Swiss. Can you name the breed whose cross breeds are there?

7. Explain composite fish culture system with example.

8. What is mixed cropping? Mention the criteria to be adopted in selecting the component crops for mixed cropping. Mention any two advantages of mixed cropping.

A. Multiple choice questions .

1. Scattering of light occurs when a beam of light is passed through -
a. blood
b. water
c. copper Sulphate Solution
d. brine

2. In order to separate two liquids using a separating funnel
a. the liquids must have appreciably different boiling points
b. two liquids must be immiscible with each other.
c. two liquids must be invisible with each other.
d. one of the liquids must be water.

3. The best method to separate the components of Ink is :
a. Chromatography.
b. Evaporation.
c. Sublimation.
d. Filtration.

4. Intercalated disk is present in :
a. Cardiac Muscle.
b. Striated Muscle.
c. Smooth Muscle.
d. Both a & c. 

5. Xylem and Phloem occurs in :
a. Connecting tissue.
b. Procambium.
c. Secondary cortex.
d. Vascular Cambium.

B. Answer the following questions .

1. Differentiate between
a. Cartilage and Bone
b. Ligament and Tendon
c. Collenchyma and Sclerenchyma
d. Blood and Lymph

2. What will happen if
a. ligaments are overstretched?
b. striated muscle contracts rapidly for a long time

1. State Newton’s Law of Gravitation. Why is it called Universal?

2. A ball when thrown vertically upwards reaches a maximum height of 19.6 m. Find the velocity with which this ball was thrown to reach this height and the time taken by it.

3. Differentiate between Mass and Weight.

4. Why is it preferable to adopt preventive measures and biological control methods for the protection of crops?

5. Compare the use of manure and fertilizers in maintaining the fertility of the soil.

6. What are the desirable characters present in bees that make them suitable for honey production?

7. Why do we get hurt on jumping on a hard surface as compared to jumping on a soft surface like a muddy floor?

8. A 5 Kg rifle fires a 10 gm bullet at a velocity of 250 m/sec. What would be the recoil velocity of the rifle?

PHYSICS

Q1. Describe Thrust. Write its SI unit.

Q2. A block of mass m is raised from position A to B by taking two different parts as shown.
Let the height AB = h. Answer the following questions.
a) What is the work done on the block in Fig 1 and Fig 2.
b) Name the energy possessed by the block at position B in both the cases.

Q3. a) An electric heater is rated 200 W. How much energy does it use in 5 hours.
b) Establish the relation between the commercial unit and SI unit of energy.

Q4. Give an example each of the following energy transformation
a) Heat energy into Mechanical energy.
b) Mechanical energy into Electric energy.

Q5. The kinetic energy of an object moving with a velocity of 5 m/s is 25 J. Find the mass of the object. What will be its kinetic energy when its velocity is 2 times? Justify your answer.

Q6. What is meant by power of machine from a 20 m high fall nearly 25 Metric tonnes of water fall per second. Calculate the equivalent power if all this energy is utilised? (g = 10m/s²)

Q7. State the meaning of 1 Pascal. A boy of mass 40 kg is standing on loose sand, if the area of his Feet is 0.04 m². Calculate the pressure exerted by the boy.

Q8. Distinguish between positive and negative work. When you lift an object, two forces act on it.
Identify these forces.

Q9. State the difference between density and relative density.

Q10. Define the following terms. State its SI unit.
a) Wavelength b) Time period c) Amplitude.

CHEMISTRY

Q1. Water molecule has hydrogen and oxygen in the ratio of 1: 8 by mass. Find the ratio number of atoms in the molecule.

Q2. a) Draw a diagram showing the observations made by Rutherford in alpha particles scattering experiments .
b) Why did Rutherford use a gold foil the experiment mentioned in part (a) ?
c) List three conclusions drawn by Rutherford from his experiment. State three features of nuclear model of an atom put forward by Rutherford.

Q3. a) State the limitations of J.J. Thomson’s model of an atom.
b) Define valency by taking the examples of magnesium ( At. No: 12) and oxygen (At. No : 8).
c) Describe Bohr’s model of atom.

Q4. a)Calculate the number of particles in each of the following :
i) 46 g of Na atoms ii) 8 g of O₂ molecule iii) 0.1 mole of carbon atoms.
b) Convert following into mole :
i) 12 g of O₂ gas ii) 20 g of water iii) 22 g of CO₂

Q5. a) Give the relationship between mole, mass and Avogadro’s number.
b) Write the chemical formula of the following compounds :
i) Hydrogen nitride ii) Hydrogen peroxide iii) Hydrogen carbide
iv) Calcium fluoride v) Iron (II) bromide vi) Silver Iodide
vii) Ammonium carbonate viii) Barium sulphate ix) Calcium phosphate

Q6. a) Calculate the molecular masses of the following compounds :

i) Acetic acid (CH₃COOH) ii) Ethanol (C₂H₅OH) iii) Carbon dioxide

b) Calculate the mass of the following :
i) 0.5 mole of N₂ gas(mass from mole of molecule)
ii) 0.5 mole of N atoms ( mass from mole of atom)
iii) 3.011 × 10²³ number of N atoms(mass from number)
iv) 6.022 × 10²³ number of N2 molecules (mass from number )

c) Calculate the number of particles in each of the following :
i) 46 g of Na atoms (number from mass)
ii) 8 g of O₂ molecules ( number of molecules from mass)
iii) 0. 1 mole of carbon atoms ( number from given moles)

Q7.a) Which of the following weighs most ?
i) 32 g of oxygen ii) 2.0 g of atoms of nitrogen
iii) 0.5 mole of iron iv) 3.011 × 10²³ atoms of C.
b) Calculate the number of atoms in each of the following : (at. masses : H = 1, S = 32 , Fe = 56 )
i) 0.08 g of hydrogen ii) 0.008 g of sulphur iii) 0.8 g of iron.

Q8.a) Write the names of the following compounds :
i) Ca₃N₂ ii) Mg(HCO₃)₂ iii) (NH₄)₂CO₃
iv) Zn3(PO₄)₃ v) Al₂(SO₄) vi) FeCl₃
b) The average atomic mass of a sample of an element X is 16.2 u. What are the percentages of isotopes 16X8 and 18 X8 in the sample.
c) Elements A, B, C and D have atomic numbers 11, 8, 1 and 17 respectively. Give the chemical for formulae of the compounds formed between (i) A and D (ii) B and C.

Q9. Substances from A to E have in them, the distribution of electrons, neutrons and protons as follows :

Making use of these data find (i)a cation (ii) an anion (iii) a pair of isotopes (iv) an atom of noble gas.

Q10. a) The nuclear composition of two atomic species X and Y is as follows:
X : 17 Protons , 18 Neutrons Y : 17 Protons , 20 Neutrons
What are their (i) atomic numbers (ii) mass numbers ? What is the relation between these two Atomic species ? Name the element or elements which they represent.
b) An atom has electronic configuration of 2, 8, 7 :
(i) What is the atomic number of the element ?
(ii) Which of the following elements have same number of valance electrons ?
N (7), F (9), P (15) and Ar (18)

BIOLOGY

Q1. Write a note on how forest influences the quality of our air, soil and water resources.

Q2. Differentiate between phanerogams and cryptogams.

Q3. a) Define nomenclature. Give the scientific name for peacock.
b) Who introduced the binominal nomenclature? Enlist the rules or conventions followed while writing the scientific names.

Q4. Give one use of lichens

Q5. Explain how HIV Aids virus affects and damages our body?

Q6. Why whales are not grouped under Pisces?

Q7. What are the criteria for classification of organisms belonging to kingdom Monera & Protista.

Q8. a) What are the different means by which infectious diseases are spread?
b) Define vectors. Give two examples of vector‐borne diseases. Explain the method of preventions of malaria.

Q9. a) What are the methods of reducing soil erosion?
b) What is Green‐ house effect?

Q10. What precautions will you take to justify “Preventions is better than cure”.