MEDIUM
7th CBSE
IMPORTANT
Earn 100

Why does a slice of apple get a brown colour if kept in air for a long time?

Important Questions on Physical and Chemical Changes

MEDIUM
7th CBSE
IMPORTANT
Exam Guru Science>Chapter 6 - Physical and Chemical Changes>Exercise 6.1>Q III
How can it be shown that setting of curd is a chemical change?
MEDIUM
7th CBSE
IMPORTANT
Exam Guru Science>Chapter 6 - Physical and Chemical Changes>Exercise 6.1>Q III
Explain why cutting of wood and burning of wood are said to be two different types of changes?
MEDIUM
7th CBSE
IMPORTANT
Exam Guru Science>Chapter 6 - Physical and Chemical Changes>Exercise 6.1>Q III
When baking soda is mixed with lemon juice, bubbles are formed with evolution of a gas. What type of change is it? Explain.
MEDIUM
7th CBSE
IMPORTANT
Exam Guru Science>Chapter 6 - Physical and Chemical Changes>Exercise 6.1>Q IV
Distinguish between a physical and chemical change.
MEDIUM
7th CBSE
IMPORTANT
Exam Guru Science>Chapter 6 - Physical and Chemical Changes>Exercise 6.1>Q IV
Explain the changes occurring in burning of candle.
MEDIUM
7th CBSE
IMPORTANT
Exam Guru Science>Chapter 6 - Physical and Chemical Changes>Exercise 6.1>Q IV
Give two changes that are harmful. Explain why you consider them harmful. How can you prevent them?
MEDIUM
7th CBSE
IMPORTANT
Exam Guru Science>Chapter 6 - Physical and Chemical Changes>Exercise 6.2>Q I
What is rust? What is the formula of rust?
MEDIUM
7th CBSE
IMPORTANT
Exam Guru Science>Chapter 6 - Physical and Chemical Changes>Exercise 6.2>Q I
How can we prevent rusting of iron? Write any two ways.