HARD
7th ICSE
IMPORTANT
Earn 100

Give three reasons why the melting of wax is considered a physical change while burning a candle is a chemical change.

Important Questions on Physical & Chemical Changes

MEDIUM
7th ICSE
IMPORTANT
Simplified Chemistry>Chapter 2 - Physical & Chemical Changes>EXERCISE>Q 4
State the observations seen, when milk in a dish is kept aside for a few hours or more. Is the change occurs- a physical change or a chemical change? Give reasons.
MEDIUM
7th ICSE
IMPORTANT
Simplified Chemistry>Chapter 2 - Physical & Chemical Changes>EXERCISE>Q 5
State what is meant by the term Interconversion of matter. Is interconversion of matter a physical change or chemical change.
HARD
7th ICSE
IMPORTANT
Simplified Chemistry>Chapter 2 - Physical & Chemical Changes>EXERCISE>Q 6
Ice kept in a beaker, slowly melts and turns into water. The water in the beaker on solidification i.e. freezing turns back to ice. Give four reasons why the change from ice to water and water back to ice is considered a physical change.
MEDIUM
7th ICSE
IMPORTANT
Simplified Chemistry>Chapter 2 - Physical & Chemical Changes>EXERCISE>Q 7

Explain the term sublimation? Is sublimation of naphthalene a physical or a chemical change. Give reason.

MEDIUM
7th ICSE
IMPORTANT
Simplified Chemistry>Chapter 2 - Physical & Chemical Changes>EXERCISE>Q 8
Ammonium chloride is also a sublimable solid. Give a reason why sublimation of ammonium chloride involves a physical and a chemical change.
MEDIUM
7th ICSE
IMPORTANT
Simplified Chemistry>Chapter 2 - Physical & Chemical Changes>EXERCISE>Q 9
State why addition of sodium chloride to water is considered a physical change, while addition of dilute sulphuric acid to zinc is considered a chemical change.
MEDIUM
7th ICSE
IMPORTANT
Simplified Chemistry>Chapter 2 - Physical & Chemical Changes>EXERCISE>Q 10
Photosynthesis is a natural process by which green plants manufacture food in the presence of sunlight.
Are any new products formed during the above process. (Yes / No)
MEDIUM
7th ICSE
IMPORTANT
Simplified Chemistry>Chapter 2 - Physical & Chemical Changes>EXERCISE>Q 10
Photosynthesis is a natural process by which green plants manufacture food in the presence of sunlight.
Can the change be reversed or is it irreversible?