Chapter 6: Water

Mars is called the red planet. What is Earth called? Explain your answer.

Which processes in the water cycle require energy?

• condensation

• evaporation

• both of them

• none of these

Why is water important for plants and animals? Select all.

• minerals are dissolved in water to be

  absorbed by roots

• as raw material

  to make food during photosynthesis

• transportation

• chemical reactions take

  place in solution form

What is the chemical formula for water?

• H2O

• H-O-H

• both of them

• none of these

Is water an element or a compound?

Select the steps in water treatment at the drinking water plant.

• sedimentation, filtration, chlorination

• evaporation, filtration, chlorination

• sedimentation, filtration, evaporation

• straining, filtration, chlorination

Label which part is land.

Can you estimate which percentage of the Earth’s surface is covered with water? __ %

What disease is caused by untreated sewage?

• diarrhoea

• cholera

• typhoid

• all of these

Which stage of water treatment for drinking water is different from the treatment of sewage?

• filtering

• sedimentation

• digestion

• chlorination