HARD
7th CBSE
IMPORTANT
Earn 100

Describe how crystals of copper sulphate are prepared.

Important Questions on Physical and Chemical Changes

HARD
7th CBSE
IMPORTANT
LEARNING SCIENCE>Chapter 6 - Physical and Chemical Changes>Exercise>Q 1
How is the burning of candle a physical as well as a chemical change?
MEDIUM
7th CBSE
IMPORTANT
LEARNING SCIENCE>Chapter 6 - Physical and Chemical Changes>Exercise>Q 2
Rusting of iron objects is faster in coastal areas than in deserts. Why?
EASY
7th CBSE
IMPORTANT
LEARNING SCIENCE>Chapter 6 - Physical and Chemical Changes>Exercise>Q 3

Change A - Animal waste is acted upon by anaerobic bacteria to produce biogas.

Change B - Biogas is burnt as fuel.
Which of these changes is a chemical change?

MEDIUM
7th CBSE
IMPORTANT
LEARNING SCIENCE>Chapter 6 - Physical and Chemical Changes>Exercise>Q 4
Which ice cube will melt the fastest? Why?
HARD
7th CBSE
IMPORTANT
LEARNING SCIENCE>Chapter 6 - Physical and Chemical Changes>Exercise>SECTION - B Value Corner
Jai was very fond of collecting coins of different metals. One day, he observed that the colour of silver and copper coins had changed. Explain the reason for his observations.