Material cycles Flashcards
Which process forms clouds?
Condensation
What is precipitation?
Rain
What is transpiration?
Where water moves through plants and is lost by evaporation
What is potable water?
Water which is safe to drink
What is desalination?
Removal of salt from sea water
How can desalination take place?
By distillation
What are some of the problems with producing potable water by distillation?
Distillation requires large amounts of heat which is expensive and can produce greenhouse gasses
During distillation, what is the purpose of the condenser?
Cools water vapour, turning it back to liquid water
What are the 3 stages in the water treatment process?
Sedimentation, filtration, chlorination
Why is chlorine added to drinking water?
To kill pathogens
What is the word equation for photosynthesis?
carbon dioxide + water –> glucose + oxygen
What is the word equation for aerobic respiration?
glucose + oxygen -> carbon dioxide + water
What is the word equation for complete combustion?
Fuel + oxygen -> carbon dioxide + water
Which processes can add carbon to the atmosphere?
respiration, combustion, decomposition
Which processes can remove carbon from the atmosphere?
photosynthesis, dissolving in oceans
How does carbon move from plants to animals?
Feeding
Where do plants get nitrogen from?
Absorbed through roots
How does nitrogen get from plants to animals?
Feeding
How is nitrogen returned to the soil from animals?
Death and excretion
How can nitrogen be fixed from the air to soil?
Bacteria or lightening
What do nitrogen-fixing bacteria do?
Fixes nitrogen from the air into soil
What do nitrifying bacteria do?
convert ammonium compounds from dead and decaying material into nitrates in the soil
What do denitrifying bacteria do?
Turn nitrates in the soil into nitrogen gas in the air
What makes legumes different from other plants?
nodules in the roots containing nitrogen fixing bacteria
What is crop rotation and why is it important?
crop rotation means growing a leguminous plant in a field every few years. The leguminous plant fixes nitrogen into the soil using bacteria in root nodules, replenishing the nutrients in the soil
Which types of organism cause decomposition?
bacteria and fungi
What effect does increasing water content have on rate of decomposition?
decomposition increases
Why does increasing water content cause rate of decomposition to increase?
Because decomposition reactions need water to take place
What effect does increasing temperature have on rate of decomposition
rate of decomposition increases, then decreases at high temperatures
What effect does increasing oxygen availability have on rate of decomposition?
Rate of decomposition increases
