MEDIUM
7th CBSE
IMPORTANT
Earn 100

What is meant by crystallisation?

Important Questions on Physical and Chemical Changes

HARD
7th CBSE
IMPORTANT
Science Booster>Chapter 7 - Physical and Chemical Changes>PRACTICE TIME>Q D
How does galvanising prevent rusting?
HARD
7th CBSE
IMPORTANT
Science Booster>Chapter 7 - Physical and Chemical Changes>PRACTICE TIME>Q E
Describe an activity to show the conditions necessary for rusting to take place.
MEDIUM
7th CBSE
IMPORTANT
Science Booster>Chapter 7 - Physical and Chemical Changes>PRACTICE TIME>Q E
Explain the various methods by which rusting can be prevented.
HARD
7th CBSE
IMPORTANT
Science Booster>Chapter 7 - Physical and Chemical Changes>PRACTICE TIME>Q E
Describe an activity to make crystals of copper sulphate.
HARD
7th CBSE
IMPORTANT
Science Booster>Chapter 7 - Physical and Chemical Changes>PRACTICE TIME>Q E
What are the characteristics of a chemical change?
MEDIUM
7th CBSE
IMPORTANT
Science Booster>Chapter 7 - Physical and Chemical Changes>PRACTICE TIME>Q E
Write the differences between a physical change and a chemical change.
HARD
7th CBSE
IMPORTANT
Science Booster>Chapter 7 - Physical and Chemical Changes>PRACTICE TIME>Q E

Look at the diagram and answer the following questions:
Question Image
Which gas is released in test tubes A and B?

HARD
7th CBSE
IMPORTANT
Science Booster>Chapter 7 - Physical and Chemical Changes>PRACTICE TIME>Q E

Look at the diagram and answer the following questions:
Question Image
What tests will you perform to identify these gases?