Science Class X

Management of Natural Resources (C10)

"Improvements in our lifestyle have resulted in greater amounts of waste generation." Give two examples to support the given statement. Suggest one change that we can incorporate in our lifestyle in order to reduce non biodegradable waste.

Management of Natural Resources (C10)

What do you understand by "Watershed Management"? List any two advantages of watershed management.

Management of Natural Resources (C10)

What is “Sustainable Management of Natural Resources”? Why is it necessary? Which one out of reuse and recycle, would you practise in your daily life and why?

Metals & Non-metals (C10)

What is reactivity series? How does the reactivity series of metals help in predicting the relative activities of various metals?

Metals & Non-metals (C10)

Suggest different chemical processes used for obtaining a metal from its oxides for metals in the middle of the reactivity series and metals towards the top of the reactivity series. Support your answer with one example each.

Metals & Non-metals (C10)

List in tabular form any three chemical properties on the basis of which metals and non-metals are differentiated.

Periodic Classification of Elements (C10)

(a) What was the basis of Mandelẽev’s classification of elements?

(b) List two achievements of Mandelẽev’s periodic tables.

(c) List any two observations which posed a challenge to Mandelẽev’s periodic law.

Periodic Classification of Elements (C10)

Write the number of periods and groups in the Modern Periodic Table. How does the metallic character of elements vary on moving (i) from left to right in a period, and (ii) down a group? Give reason to justify your answer.

Periodic Classification of Elements (C10)

Na, Mg and Al are the elements of the 3rd period of the Modern Periodic Table having group number 1, 2 and 13 respectively. Which one of these elements has the (a) highest valency, (b) largest atomic radius, and (c) maximum chemical reactivity? Justify your answer stating the reason for each.

Periodic Classification of Elements (C10)

An element "X" has mass number 35 and the number of neutrons is 18. Identify the group number and period of "X".

Periodic Classification of Elements (C10)

Differentiate between the arrangement of elements in Mendeleev’s periodic table and Modern periodic table.

Periodic Classification of Elements (C10)

Explain giving justification the trends in the following properties of elements, on moving from left to right in a period, in the Modern periodic Table.

  1. Variation of valency.
  2. Change of atomic radius.
  3. Metallic to non-metallic character.
  4. Electronegative character.
  5. Nature of oxides.

Life Processes (C10)

Name the balloon likes structures present in lungs. List its two functions.

Life Processes (C10)

(a) Name the process and explain the type of nutrition found in green plants. List the raw materials required for this process. Give chemical equation for the mentioned process.

(b) Write three events that occur during this process.

Reproduction (C10)

Explain how, offspring and parents of organisms reproducing sexually have the same number of chromosomes.

Reproduction (C10)

List three techniques that have been developed to prevent pregnancy. Which one of these techniques is not meant for males? How does the use of these techniques have a direct impact on the health and prosperity of a family?

Reproduction (C10)

What is vegetative propagation? State two advantages and two disadvantages of this method.

Reproduction (C10)

What is variation? How is variation created in a population? How does the creation of variation in a species promote survival?

Human Eye & Colourful World (C10)

Why does the sun appear reddish early in the morning? Will this phenomenon be observed by an astronaut on the Moon? Give reason to justify your answer.

Human Eye & Colourful World (C10)

Noopur needs a lens of power -4.5D for correction of her vision.

  1. What kind of defect in vision is she suffering from?
  2. What is the focal length and nature of the corrective lens?
  3. Draw ray diagrams showing the (a) defected eye and (b) correction for this defect.
  4. What are the causes of this defect?

Science Practical (C10) Human Eye & Colourful World (C10)

Draw a path of light ray passing through a prism. Label angle of incidence and angle of deviation in the ray diagram.

Human Eye & Colourful World (C10)

State the cause of dispersion of white light by a glass prism. How did Newton, using two identical glass prisms, show that white light is made of seven colours? Draw a ray diagram to show the path of a narrow beam of white light, through a combination of two identical prisms arranged together in inverted position with respect to each other, when it is allowed to fall obliquely on one of the faces of the first prism of the combination.

Magnetic Effects (C10)

Name the electric device that converts mechanical energy into electrical energy. Draw the labelled diagram and explain the principle involved in this device.

Magnetic Effects (C10)

With the help of a labelled circuit diagram wire describe an activity to illustrate the pattern of the magnetic field lines around a straight current carrying long conducting wire.

  1. Name the rule that is used to find the direction of magnetic field associated with a current carrying conductor.
  2. Is there a similar magnetic field produced around a thin beam of moving (a) alpha particles and (b) neutrons? Justify your answer.

Magnetic Effects (C10)

(a) What are magnetic field lines? How is the direction of magnetic field at a point in a magnetic field determined using field lines?

(b) Two circular coils ‘X’ and ‘Y’ are placed close to each other. If the current in the coil ‘X’ is changed, will some current be induced in the coil ‘Y’? Give reason.

(c) State ‘Fleming’s right hand rule”.

Science Practical (C10)

Draw a labelled diagram of the experimental set up for the study of liberation of carbon dioxide gas during respiration.

Science Practical (C10)

In a school laboratory the students are studying the properties of ethanoic acid through certain experiments. How can they test its acidic nature ? Give two tests.

Science Practical (C10)

In the laboratory of a school, the sample of hard water is not available “to study the comparative cleaning capacity of a sample of soap in soft and hard water”. Which salt from the laboratory can be added to tap water to make it hard ? In the experiment how is cleaning capacity of soap compared ?

Management of Natural Resources (C10)

What is a dam? Why do we seek to build large dams? While building large dams, which three main problems should particularly be addressed to maintain peace among local people ? Mention them.

Our Environment (C10) Management of Natural Resources (C10)

Students in a school listened to the news read in the morning assembly that the mountain of garbage in Delhi, suddenly exploded and various vehicles got buried under it. Several people were also injured and there was traffic jam all around. In the brain storming session the teacher also discussed this issue and asked the students to find out a solution to the problem of garbage. Finally they arrived at two main points - one is self management of the garbage we produce and the second is to generate less garbage at individual level.

(a) Suggest two measures to manage the garbage we produce.

(b) As an individual, what can we do to generate the least garbage ? Give two points.

(c) List two values the teacher instilled in his students in this episode.

Reflection & Refraction (C10)

If the image formed by a spherical mirror for all positions of the object placed in front of it is always erect and diminished, what type of mirror is it? Draw a labelled ray diagram to support your answer.

Carbon & its Compounds (C10)

A compound ‘X’ on heating with excess conc. sulphuric acid at 443 K gives an unsaturated compound ‘Y’. ‘X’ also reacts with sodium metal to evolve a colourless gas ‘Z’. Identify ‘X’, ‘Y’ and ‘Z’. Write the equation of the chemical reaction of formation of ‘Y’ and also write the role of sulphuric acid in the reaction.

Control & Coordination (C10)

Write a and b in the given flow chart of neuron through which information travels as an electrical impulse.

Reflection & Refraction (C10)

What is meant by power of a lens? Write its SI unit. A student uses a lens of focal length 40 cm and another of –20 cm. Write the nature and power of each lens.

Reflection & Refraction (C10)

State the laws of refraction of light. Explain the term 'absolute refractive index of a medium' and write an expression to relate it with the speed of light in vacuum.

Control & Coordination (C10)

Name the hormones secreted by the following endocrine glands and specify one function of each:

(a) Thyroid (b) Pituitary (c) Pancreas

Reproduction (C10)

Write one main difference between asexual and sexual mode of reproduction. Which species is likely to have comparatively better chances of survival - the one reproducing asexually or the one reproducing sexually? Give reason to justify your answer.

Electricity (C10)

Why are alloys commonly used in electrical heating devices? Give reason.

Electricity (C10)

Why are metals good conductors of electricity whereas glass is a bad conductor of electricity? Give reason.

Electricity (C10)

List the factors on which the resistance of a conductor in the shape of a wire depends.

Acids, Bases & Salts (C10)

2 mL of sodium hydroxide solution is added to a few pieces of granulated zinc metal taken in a test tube. When the contents are warmed, a gas evolves which is bubbled through a soap solution before testing. Write the equation of the chemical reaction involved and the test to detect the gas. Name the gas which will be evolved when the same metal reacts with dilute solution of a strong acid.