Cycles

Question 1

Water cycle

Answer 1

• Rivers flow in to lakes and eventually the water returns to the ocean
• Water evaporates from water sources to form water vapor
• As the air rises it cools and water vapor in it condenses to form clouds
• As water droplets get too large and heavy they fall as rain or snow

Question 2

Potable water

Answer 2

Drinking water

Question 3

Making water potable

Answer 3

Water must be treated with chemicals and filtered to remove dirt, pathogens and toxic substances.

Question 4

Water desalination

Answer 4

Obtaining water from the sea and making it drinkable

Question 5

Carbon cycle

Answer 5

• When you burn fossils fuels, you release carbon into the air as carbon dioxide
• During photosynthesis, plants absorb co2 and convert it into carbon compounds
• Carbon compounds in plants are passed to animals when they eat plants
• Respiration releases carbon dioxide into the air as carbon dioxide gas
• Dead organisms that are not decomposed may eventually form fossil fuels