MEDIUM
Earn 100

What is the difference between refrigeration and freezing?

Important Questions on Physical and Chemical Changes

EASY
Which of the following is not an example of a biomass energy source?
EASY
Write down the process of evolution of fossil fuels on Earth.
MEDIUM
Write a short note on: Nuclear Energy
MEDIUM
Explain how is nuclear energy generated in power reactors. How is electricity produced from nuclear energy?
EASY
By what name is biogas popularly known in India?
MEDIUM
List any three differences between nuclear fission reaction and nuclear fusion reaction.
MEDIUM
Useful substance in preparation of freezing mixture is 
EASY
Which of the following is not an example of a bio-mass energy source?
EASY
 State two ways to prevent the rusting of iron.
EASY

Write names of any two energies produced in ocean.

MEDIUM

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
Write the name of two elements used as nuclear energy.
EASY
Which one of the following is an example of Biomass energy source.
MEDIUM
Write any four differences between nuclear fusion and nuclear fission.
EASY
Nowadays bio-diesel is used in transportation vehicles as an alternate to diesel. Write two advantages of this measure.
EASY

Write down the two benefits of use of solar energy.

EASY
On heating, _____ process changes the state of matter.
EASY
Select the material that undergoes the change.
  • A sheet of paper cut with a pair of scissors.