Define the following term.

Rusting of iron 

Important Questions on Physical and Chemical Changes

MEDIUM

7th CBSE

IMPORTANT

Science 7>Chapter 6 - Physical and Chemical Changes>Summative ASSESSMENT>Q 5

Define the following term:

Crystallisation

HARD

7th CBSE

IMPORTANT

Science 7>Chapter 6 - Physical and Chemical Changes>Summative ASSESSMENT>Q 1

A bottle containing a perfume is by mistake left open. After a few days, its volume was found to have reduced to half. Explain giving reason.

HARD

7th CBSE

IMPORTANT

Science 7>Chapter 6 - Physical and Chemical Changes>Summative ASSESSMENT>Q 2

Which property of iron is modified in stainless steel? What is done to do so?

HARD

7th CBSE

IMPORTANT

Science 7>Chapter 6 - Physical and Chemical Changes>Summative ASSESSMENT>Q 3

Rusting of iron requires air and water (moisture). Does the quality of air and water affect the rusting process?

MEDIUM

7th CBSE

IMPORTANT

Science 7>Chapter 6 - Physical and Chemical Changes>FORMATIVE & SUMMATIVE ASSESSMENTS>Q 1

Which of the following is not a physical change?

EASY

7th CBSE

IMPORTANT

Science 7>Chapter 6 - Physical and Chemical Changes>FORMATIVE & SUMMATIVE ASSESSMENTS>Q 2

Which of the following is a chemical change?

MEDIUM

7th CBSE

IMPORTANT

Science 7>Chapter 6 - Physical and Chemical Changes>FORMATIVE & SUMMATIVE ASSESSMENTS>Q 3

Chemical changes are
 

MEDIUM

7th CBSE

IMPORTANT

Science 7>Chapter 6 - Physical and Chemical Changes>FORMATIVE & SUMMATIVE ASSESSMENTS>Q 4

During the dissolution of urea, heat (Hint: When urea is dissolved in water cooling is observed)