Why do hcl hno3 show acidic

Differentiate between regular and diffused reflection. Does diffused reflection mean the failure of the laws of reflection? Mention against each of the following whether regular or diffused reflection will take place when a beam of light strikes. Justify your answer in each case. State the laws of reflection. Describe an activity to show that the incident ray, the reflected ray and the normal at the point of incidence lie in the same plane. Fill in the blanks in the following. Angle of incidence is equal to the angle of reflection.

Describe the construction of a kaleidoscope. Draw a labelled sketch of the human eye. Gurmit wanted to perform Activity Her teacher advised her not to do so. Explain how you can take care of your eyes. How many images of a candle will be formed if it is placed between two parallel plane mirrors separated by 40 cm? Two mirrors meet at right angles. Draw the reflected ray from the second mirror.

Boojho stands at A just on the side of a plane mirror as shown in Fig. Can he see himself in the mirror? Also can he see the image of objects situated at P, Q and R? Choose the correct answer in Questions Which of the following is NOT a member of the solar system?

Which of the following is NOT a planet of the sun? Phases of the moon occur because.. Mark the following statements as true T or false F. Match items in column A with one or more items in column B. In which part of the sky can you find Venus if it is visible as an evening star? Name the largest planet of the solar system. What is a constellation? Name any two constellations. Draw sketches to show the relative positions of prominent stars in a Ursa Major and b Orion Name two objects other than planets which are members of the solar system.

Explain how you can locate the Pole Star with the help of Ursa Major. Name the petroleum product used for surfacing of roads. Do all the stars in the sky move? Why is the distance between stars expressed in light years? What do you understand by the statement that a star is eight light years away from the Earth?

The radius of Jupiter is 11 times the radius of the Earth. Calculate the ratio of the volumes of Jupiter and the Earth.

How many Earths can Jupiter accomodate? Boojho made the following sketch Fig. Is the sketch correct? If not, correct it. State similarities and differences between the laboratory thermometer and the clinical thermometer.

Describe how coal is formed from dead vegetation. What is this process called? Give two examples each of conductors and insulators of heat. Describe characteristics and uses of coke.

Explain the process of formation of petroleum. Discuss why wearing more layers of clothing during winter keeps us warmer than wearing just one thick piece of clothing. Look at Fig. Mark where the heat is being transferred by conduction, by convection and by radiation.

The following Table shows the total power shortage in India from — Show the data in the form of a graph. Plot shortage percentage for the years on the Y-axis and the year on the X-axis. In places of hot climate it is advised that the outer walls of houses be painted white. The temperature of the mixture will be Fill in the blanks. The heat will a flow from iron ball to water. A wooden spoon is dipped in a cup of ice cream. Its other end a becomes cold by the process of conduction. Stainless steel pans are usually provided with copper bottoms.

The reason for this could be that a copper bottom makes the pan more durable Fill the missing word in the blank spaces in the following statements: a Wind is——————air. Suggest two methods to find out wind direction at a given place. State two experiences that made you think that air exerts pressure other than those given in the text. You want to buy a house.

Would you like to buy a house having windows but no ventilators? Explain why holes are made in hanging banners and hoardings. What planning is required in advance to deal with the situation created by a cyclone? Which one of the following place is unlikely to be affected by a cyclone. Explain how the use of CNG in automobiles has reduced pollution in our cities. Compare LPG and wood as fuels Give reasons. Make a labelled diagram of a candle flame. Classify the following as motion along a straight line, circular or oscillatory motion: i Motion of your hands while running.

Which of the following are not correct? A simple pendulum takes 32 s to complete 20 oscillations. What is the time period of the pendulum? The distance between two stations is km. A train takes 4 hours to cover this distance. Calculate the speed of the train. Name the unit in which the calorific value of a fuel is expressed. The odometer of a car reads What is the distance moved by the car,..

Explain how CO2 is able to control fires. It is difficult to burn a heap of green leaves but dry leaves catch fire easily. Which zone of a flame does a goldsmith use for melting gold and silver and why? In an experiment 4. The heat produced was measured to be , kJ. Calculate the calorific value of the fuel. Can the process of rusting be called combustion? Abida and Ramesh were doing an experiment in which water was to be heated in a beaker. Abida kept the beaker near the wick in the yellow part of the candle flame.

Choose the correct option. Which of the following does not yield wool? What is meant by the following terms? Given below is a sequence of steps in the processing of wool. Which are the missing steps?

Which of the following relations is correct? The total distance covered by the car is: i km ii 25 km iii 15 km iv 10 km Out of the following, which are the two terms related to silk production? Sericulture, floriculture, moriculture, apiculture and silviculture.

If a distance of metres is shown by 1 cm in these photographs Which one of them is moving faster? Which of the following distance-time graphs shows a truck moving with speed which is not constant?

Draw the circuit diagram to represent the circuit shown in Fig. Draw lines to indicate how you will connect their terminals with wires to make a battery of four cells. The bulb in the circuit shown in Fig. Can you identify the problem? Make necessary changes in the circuit to make the bulb glow.

Name any two effects of electric current. When the current is switched on through a wire, a compass needle kept nearby gets deflected from its north-south position. Will the compass needle show deflection when the switch in the circuit shown by Fig.

Do you think an electromagnet can be used for separating plastic bags from a garbage heap? An electrician is carrying out some repairs in your house. He wants to replace a fuse by a piece of wire. Would you agree? Give reasons for your response. Given below is a crossword puzzle based on this lesson. Use hints to fill in the blank spaces with letters that complete the words. Zubeda made an electric circuit using a cell holder shown in Fig. State differences between acids and bases.

In the circuit shown in Fig. State the characteristics of the image formed by a plane mirror. Find out the letters of English alphabet or any other language known to you in which the image formed in a plane mirror appears exactly like the letter itself. Discuss your findings. What is a virtual image? Give one situation where a virtual image is formed. State two differences between a convex and a concave lens.

Give one use each of a concave and a convex mirror. Which type of mirror can form a real image? Which type of lens forms always a virtual image?

Ammonia is found in many household products, such as window cleaners. It turns red litmus blue. What is its nature? Name the source from which litmus solution is obtained. What is the use of this solution? How would you verify it? Describe the process of neutralisation with the help of an example. But, unfortunately, these are not labelled. He has to serve the drinks on the demand of customers.

Explain why: a An antacid tablet is taken when you suffer from acidity. Three liquids are given to you. One is hydrochloric acid, another is sodium hydroxide and third is a sugar solution. How will you identify them? You have only turmeric indicator. David is observing his image in a plane mirror. The distance between the mirror and his image is 4 m. If he moves 1 m towards the mirror, then the distance between David and his image will be i 3 m ii 5 m iii 6 m iv 8 m Blue litmus paper is dipped in a solution.

It remains blue. What is the nature of the solution? The rear view mirror of a car is a plane mirror. The driver sees in his rear view mirror the image of a truck parked behind his car Consider the following statements: a Both acids and bases change colour of all indicators. Classify the changes involved in the following processes as physical or chemical changes: State whether the following statements are true or false.

In case a statement is false, write the corrected statement in your notebook. When baking soda is mixed with lemon juice, bubbles are formed with the evolution of a gas. What type of change is it? When a candle burns, both physical and chemical changes take place. Identify these changes. Give another example of a familiar process in which both the chemical and physical changes take place.

Give two examples each, of modes of transport used on land, water and air. Why can a pace or a footstep not be used as a standard unit of length? Arrange the following lengths in their increasing magnitude: 1 metre, 1 centimetre, 1 kilometre,1 millimetre. The height of a person is 1. Express it into cm and mm. How would you show that setting of curd is a chemical change? Explain why burning of wood and cutting it into small pieces are considered as two different types of changes Describe how crystals of copper sulphate are prepared.

Explain how painting of an iron gate prevents it from rusting. Explain why rusting of iron objects is faster in coastal areas than in deserts. The gas we use in the kitchen is called liquified petroleum gas LPG. In the cylinder it exist as a liquid. When it comes out from the cylinder it becomes a gas Change — A then it burns Change — B. Anaerobic bacteria digest animal waste and produce biogas Change — A.

The biogas is then burnt as fuel Change — B. The following statements pertain to these changes. Choose the correct one. Classify the following fibres as natural or synthetic: nylon, wool, cotton, silk, polyester, jute State whether the following statements are true or false: a Yarn is made from fibres.

From which parts of the plant cotton and jute are obtained? Name two items that are made from coconut fibre. Explain the process of making yarn from fibre. While measuring the length of a knitting needle, the reading of the scale at one end is 3.

What is the length of the needle? Name five objects which can be made from wood. Select those objects from the following which shine: Glass bowl, plastic toy, steel spoon, cotton shirt Write the similarities and differences between the motion of a bicycle and a ceiling fan that has been switched on. Why would you not like to use a measuring tape made of an elastic material like rubber to measure distance? What would be some of the problems you Give two examples of periodic motion.

Rearrange the boxes given below to make a sentence that helps us understand opaque objects. Classify the objects or materials given below as opaque, transparent or translucent and luminous or non-luminous: Can you think of creating a shape that would give a circular shadow if held in one way and a rectangular shadow if held in another way?

In a completely dark room, if you hold up a mirror in front of you, will you see a reflection of yourself in the mirror? Explain why the bulb would not glow in the arrangement shown in Fig. Complete the drawing shown in Fig What is the purpose of using an electric switch? Name some electrical gadgets that have switches built into them. Would the bulb glow after completing the circuit shown in Fig.

Would the bulb glow in the circuit shown in Fig. Match the objects given below with the materials from which they could be made. Remember, an object could be made from more than one material and a given material could be used for making many objects. State whether the statements given below are True or False. Given below are the names of some objects and materials: Water, basket ball, orange, sugar, globe, apple and earthen pitcher Group them as: a Round shaped and other shapes b Eatables and non eatables Using the "conduction tester" on an object it was found that the bulb begins to glow.

Is that object a conductor or an insulator? Why should an electrician use rubber gloves while repairing an electric switch at your home?

The handles of the tools like screwdrivers and pliers used by electricians for repair work usually have plastic or rubber covers on them.

List all items known to you that float on water. Check and see if they will float on an oil or kerosene. What is winnowing? Where is it used? How will you separate husk or dirt particles from a given sample of pulses before cooking? What is sieving? How will you separate sand and water from their mixture? State whether the following statements are true or false: i A cylindrical magnet has only one pole. It was observed that a pencil sharpener gets attracted by both the poles of a magnet although its body is made of plastic.

Name a material that might have been used to make some part of it. Is it possible to separate sugar mixed with wheat flour? If yes, how will you do it?

How would you obtain clear water from a sample of muddy water? Column I shows different positions in which one pole of a magnet is placed near that of the other. Column II indicates the resulting action between them for each situation. True or false?

Lemonade is prepared by mixing lemon juice and sugar in water. You wish to add ice to cool it. Should you add ice to the lemonade before or after dissolving sugar? In which case would it be possible to dissolve more sugar? Write any two properties of a magnet. To walk through a waterlogged area, you usually shorten the length of your dress by folding it. Can this change be reversed? Where are poles of a bar magnet located? You accidentally dropped your favourite toy and broke it. This is a change you did not want.

A bar magnet has no markings to indicate its poles. How would you find out near which end is its north pole located? You are given an iron strip. How will you make it into a magnet? How is a compass used to find directions? Some changes are listed in the following table.

For each change, write in the blank column, whether the change can be reversed or not. A drawing sheet changes when you draw a picture on it. Can you reverse this change? Give examples to explain the difference between changes that can or cannot be reversed. It becomes hard on drying to keep the fractured bone immobilised. Can the change in POP be reversed? A bag of cement lying in the open gets wet due to rain during the night. The next day the sun shines brightly.

Do you think the changes, which have occurred in the cement, could be reversed? The kidneys in human beings are a part of the system for a nutrition. The xylem in plants are responsible for a transport of water. The autotrophic mode of nutrition requires a carbon dioxide and water. A magnet was brought from different directions towards a toy boat that has been floating in water in a tub The breakdown of pyruvate to give carbon dioxide, water and energy takes place in a cytoplasm.

How are fats digested in our bodies? Where does this process take place? What is the role of saliva in the digestion of food? What are the necessary conditions for autotrophic nutrition and what are its byproducts? What are the differences between aerobic and anaerobic respiration? Name some organisms that use the anaerobic mode of respiration. How are the alveoli designed to maximise the exchange of gases? What would be the consequences of a deficiency of haemoglobin in our bodies?

Describe double circulation of blood in human beings. Why is it necessary? What are the differences between the transport of materials in xylem and phloem? Compare the functioning of alveoli in the lungs and nephrons in the kidneys with respect to their structure and functioning.

Which of the following is a plant hormone? The gap between two neurons is called a a dendrite. The brain is responsible for a thinking. What is the function of receptors in our body? Think of situations where receptors do not work properly. What problems are likely to arise? Draw the structure of a neuron and explain its function. How does phototropism occur in plants? Which signals will get disrupted in case of a spinal cord injury? How does chemical coordination occur in plants?

What is the need for a system of control and coordination in an organism? How are involuntary actions and reflex actions different from each other? Compare and contrast nervous and hormonal mechanisms for control and coordination in animals. What is the difference between the manner in which movement takes place in a sensitive plant and the movement in our legs?

Asexual reproduction takes place through budding in a amoeba. Which of the following is not a part of the female reproductive system in human beings? What are the functions performed by the testis in human beings? Why does menstruation occur? Draw a labelled diagram of the longitudinal section of a flower. What are the different methods of contraception? How are the modes for reproduction different in unicellular and multicellular organisms? How does reproduction help in providing stability to populations of species?

What could be the reasons for adopting contraceptive methods? A Mendelian experiment consisted of breeding tall pea plants bearing violet flowers with short pea plants bearing white flowers. In evolutionary terms, we have more in common with a a Chinese school-boy. A study found that children with light-coloured eyes are likely to have parents with light-coloured eyes.

On this basis, can we say anything about whether the light eye colour trait is dominant or recessive? Why or why not? How are the areas of study — evolution and classification — interlinked? Explain the terms analogous and homologous organs with examples. Outline a project which aims to find the dominant coat colour in dogs.

Explain the importance of fossils in deciding evolutionary relationships What evidence do we have for the origin of life from inanimate matter? Explain how sexual reproduction gives rise to more viable variations than asexual reproduction. How does this affect the evolution of those organisms that reproduce sexually? How is the equal genetic contribution of male and female parents ensured in the progeny?

Only variations that confer an advantage to an individual organism will survive in a population. Do you agree with this statement? Which of the following groups contain only biodegradable items? What will happen if we kill all the organisms in one trophic level?

Will the impact of removing all the organisms in a trophic level be different for different trophic levels? Can the organisms of any trophic level be removed without causing any damage to the ecosystem? What is biological magnification? Will the levels of this magnification be different at different levels of the ecosystem?

What are the problems caused by the non-biodegradable wastes that we generate? If all the waste we generate is biodegradable, will this have no impact on the environment? Why is damage to the ozone layer a cause for concern? What steps are being taken to limit this damage? What changes would you suggest in your home in order to be environment-friendly?

Can you suggest some changes in your school which would make it environment-friendly? We saw in this chapter that there are four main stakeholders when it comes to forests and wildlife. Which among these should have the authority to decide the management of forest produce?

Why do you think so? How can you as an individual contribute or make a difference to the management of a forests and wildlife, b water resources and c coal and petroleum? What can you as an individual do to reduce your consumption of the various natural resources? List five things you have done over the last one week to — a conserve our natural resources. On the basis of the issues raised in this chapter, what changes would you incorporate in your lifestyle in a move towards a sustainable use of our resources?

Make a comparison and write down ways in which plant cells are different from animal cells. How is a prokaryotic cell different from a eukaryotic cell? What would happen if the plasma membrane ruptures or breaks down? What would happen to the life of a cell if there was no Golgi apparatus? Which organelle is known as the powerhouse of the cell? Where do the lipids and proteins constituting the cell membrane get synthesised? How does an Amoeba obtain its food? What is osmosis? Carry out the following osmosis experiment: Take four peeled potato halves and scoos each one out to make potato cups.

One of these potato cups should be made from a boiled potato. Which type of cell division is required for growth and repair of body and which type is involved in formation of gametes? How many types of elements together make up the xylem tissue? Name them. How are simple tissues different from complex tissues in plants? Differentiate between parenchyma, collenchyma and sclerenchyma on the basis of their cell wall.

What are the functions of the stomata? Diagrammatically show the difference between the three types of muscle fibres. What is the specific function of the cardiac muscle?

Draw a labelled diagram of a neuron. Which of the following statements is not a correct statement about the trends when going from left to right across the periods of periodic table. By considering their position in the periodic table, which one of the following elements would you expect to have maximum metallic character. In the modem periodic table, which are the metals among the first ten elements. Helium is an unreactive gas and neon is a gas of extremely low reactivity.

What, if anything, do their atoms have in common. Lithium, sodium, potassium are all metals that react with water to liberate hydrogen gas. Is there any similarity in the atoms of these elements.

Name three elements with filled outermost shells. Name two elements that have two electrons in their outermost shells. Compounds similar to glucose or alcohol also do contain hydrogen element but they do not show signs of acidic nature. This is due to the fact that the hydrogen in them will not separate as like the hydrogen in the acids.

They will not separate to become hydrogen ions, on dissolving in the water. Question Papers. Question Papers Textbook Solutions MCQ Online Tests 3. Important Solutions