MEDIUM
Earn 100

Place an ice cube on a plate for 10 minutes. What did you notice? Is there any change in the ice cube? 

Important Questions on Changes Around Us

EASY
Science>Chemistry>Changes Around Us>Ways to Bring About Changes
Write down the process of evolution of fossil fuels on Earth.
MEDIUM
Science>Chemistry>Changes Around Us>Ways to Bring About Changes
Write any four differences between nuclear fusion and nuclear fission.
MEDIUM
Science>Chemistry>Changes Around Us>Ways to Bring About Changes
List any three differences between nuclear fission reaction and nuclear fusion reaction.
EASY
Science>Chemistry>Changes Around Us>Ways to Bring About Changes
By what name is biogas popularly known in India?
EASY
Science>Chemistry>Changes Around Us>Ways to Bring About Changes
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>Ways to Bring About Changes
Write the name of two elements used as nuclear energy.
EASY
Science>Chemistry>Changes Around Us>Ways to Bring About Changes
Name two uses biogas.
EASY
Science>Chemistry>Changes Around Us>Ways to Bring About Changes
Which one of the following is an example of Biomass energy source.
MEDIUM
Science>Chemistry>Changes Around Us>Ways to Bring About Changes
Explain how is nuclear energy generated in power reactors. How is electricity produced from nuclear energy?
EASY
Science>Chemistry>Changes Around Us>Ways to Bring About Changes
Uranium is used to obtain:
MEDIUM
Science>Chemistry>Changes Around Us>Ways to Bring About Changes
Write a short note on: Nuclear Energy
EASY
Science>Chemistry>Changes Around Us>Ways to Bring About Changes

Write down the two benefits of use of solar energy.

EASY
Science>Chemistry>Changes Around Us>Ways to Bring About Changes
 State two ways to prevent the rusting of iron.
EASY
Science>Chemistry>Changes Around Us>Ways to Bring About Changes
Which of the following is not an example of a biomass energy source?
MEDIUM
Science>Chemistry>Changes Around Us>Ways to Bring About Changes

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

MEDIUM
Science>Chemistry>Changes Around Us>Ways to Bring About Changes
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>Ways to Bring About Changes
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>Ways to Bring About Changes
Which of the following is not an example of a bio-mass energy source?
EASY
Science>Chemistry>Changes Around Us>Ways to Bring About Changes

Write names of any two energies produced in ocean.

MEDIUM
Science>Chemistry>Changes Around Us>Ways to Bring About Changes
Useful substance in preparation of freezing mixture is