MEDIUM
8th ICSE
IMPORTANT
Earn 100

Which of the following are ‘pure substances’?
Ice, Milk, Iron, Hydrochloric acid, Calcium oxide, Mercury, Brick, Wood, Air

Important Questions on Elements, Compounds and Mixtures

EASY
8th ICSE
IMPORTANT
Lakhmir Singh's Science - Chemistry>Chapter 3 - Elements, Compounds and Mixtures>EXERCISES>Q 6
State three reasons why you think air is a mixture and water is a compound.
MEDIUM
8th ICSE
IMPORTANT
Lakhmir Singh's Science - Chemistry>Chapter 3 - Elements, Compounds and Mixtures>EXERCISES>Q 7
What is the difference between threshing and winnowing?
EASY
8th ICSE
IMPORTANT
Lakhmir Singh's Science - Chemistry>Chapter 3 - Elements, Compounds and Mixtures>EXERCISES>Q 8
Which one of the two methods- sieving or winnowing, is better for the separation of bran from wheat flour?
EASY
8th ICSE
IMPORTANT
Lakhmir Singh's Science - Chemistry>Chapter 3 - Elements, Compounds and Mixtures>EXERCISES>Q 10
How do you separate a mixture of salt and ammonium chloride?
HARD
8th ICSE
IMPORTANT
Lakhmir Singh's Science - Chemistry>Chapter 3 - Elements, Compounds and Mixtures>EXERCISES>Q 12
What is the difference between simple distillation and fractional distillation?
EASY
8th ICSE
IMPORTANT
Lakhmir Singh's Science - Chemistry>Chapter 3 - Elements, Compounds and Mixtures>EXERCISES>Q 1

Why do we need to separate different components of a mixture? Explain with examples.

HARD
8th ICSE
IMPORTANT
Lakhmir Singh's Science - Chemistry>Chapter 3 - Elements, Compounds and Mixtures>EXERCISES>Q 2
Name a solid, a liquid and a gaseous mixture. How will you separate a mixture of sugar and sand?
MEDIUM
8th ICSE
IMPORTANT
Lakhmir Singh's Science - Chemistry>Chapter 3 - Elements, Compounds and Mixtures>EXERCISES>Q 3
What is fractional distillation? What is the use of fractionating column in fractional distillation?