Unit 2.3 Pre-lesson Quiz

How many water impurities is mentioned in the video 1?

• 1

• 2

• 3

• 4

Which type of impurities does salt belong to?

• insoluble impurities

• soluble impurities

• microorganism

How many water purification method is mentioned in the video 2?

• 1

• 2

• 3

• 4

Which of the following can be removed by filtration?

• Heavy insoluble impurities

• Soluble impurities

• Insoluble impurities suspending in water

• Microorganisms

In filtration, the impurities remaining on the filter paper is called the ____________.

Which of the following statements about water purification is INCORRECT?

• Water purification is needed because natural water contains many impurities.

• The simplest way for purifying water is sedimentation.

• Filtered water is not safe for drinking because it still contains microorganisms.

• Distillation can only be used to remove soluble impurities and microorganisms.