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Identify as physical change or chemical change.

When jelly cubes are heated, they melt.

33.33% studentsanswered this correctly

Important Questions on Changes Around Us

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Science>Chemistry>Changes Around Us>Changes of State
List any three differences between nuclear fission reaction and nuclear fusion reaction.
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Science>Chemistry>Changes Around Us>Changes of State

Write names of any two energies produced in ocean.

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Science>Chemistry>Changes Around Us>Changes of State
Explain how is nuclear energy generated in power reactors. How is electricity produced from nuclear energy?
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Science>Chemistry>Changes Around Us>Changes of State
Write down the process of evolution of fossil fuels on Earth.
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Science>Chemistry>Changes Around Us>Changes of State
Which of the following is not an example of a biomass energy source?
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Science>Chemistry>Changes Around Us>Changes of State
Name two uses biogas.
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Science>Chemistry>Changes Around Us>Changes of State
Nowadays bio-diesel is used in transportation vehicles as an alternate to diesel. Write two advantages of this measure.
EASY
Science>Chemistry>Changes Around Us>Changes of State
 State two ways to prevent the rusting of iron.
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Science>Chemistry>Changes Around Us>Changes of State

Which of the following are physical changes?

(a) Melting of iron metal        (b) Rusting of iron

(c) Bending of an iron rod     (d) Drawing a wire of iron metal

EASY
Science>Chemistry>Changes Around Us>Changes of State
Which one of the following is an example of Biomass energy source.
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Science>Chemistry>Changes Around Us>Changes of State
Write the name of two elements used as nuclear energy.
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Science>Chemistry>Changes Around Us>Changes of State
Uranium is used to obtain:
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Science>Chemistry>Changes Around Us>Changes of State
By what name is biogas popularly known in India?
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Science>Chemistry>Changes Around Us>Changes of State
Write any four differences between nuclear fusion and nuclear fission.
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Science>Chemistry>Changes Around Us>Changes of State
Write a short note on: Nuclear Energy
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Science>Chemistry>Changes Around Us>Changes of State
1 kg of water, at 20 °C is heated in an electric kettle whose heating element has a mean (temperature averaged) resistance of 20 Ω. The rms voltage in the mains is 200 V. Ignoring heat loss from the kettle, time taken for water to evaporate fully is close to
[ Specific heat of water =4200 J kg-1 °C-1 Latent heat of water =2260 kJ kg-1 ]
EASY
Science>Chemistry>Changes Around Us>Changes of State
A piece of ice falls from a height h so that it melts completely. Only one-quarter of the heat produced is absorbed by the ice and all energy of ice gets converted into heat during its fall. The value of h is:
(Latent heat of ice is 3.4×105 J kg-1 and g=10 N kg-1)
EASY
Science>Chemistry>Changes Around Us>Changes of State

Write down the two benefits of use of solar energy.

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Science>Chemistry>Changes Around Us>Changes of State
Which of the following is not an example of a bio-mass energy source?
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Science>Chemistry>Changes Around Us>Changes of State
Useful substance in preparation of freezing mixture is