geochemical cycles Flashcards
What is the phosphorus cycle?
Phosphorus is essential for life but is found in limited quantities.
What is the long-term cycle of phosphorus?
Found in bedrock as phosphate ions (PO₄³⁻).
What is the short-term cycle of phosphorus?
Wastes from living organisms are recycled by decomposers.
How do phosphates enter the food chain?
Phosphates enter the food chain through photosynthetic organisms.
What is an algal bloom?
Overgrowth of algae can reduce oxygen in aquatic environments, harming aquatic life.
What measure has been taken to control algal blooms?
Phosphates in soaps have been banned.
What is nitrogen fixation?
Nitrogen gas (N₂) is converted to ammonium (NH₄⁺) by bacteria or lightning.
What is ammonification?
Ammonium is converted to nitrite (NO₂⁻) or nitrate (NO₃⁻).
What is denitrification?
Nitrate/nitrite is converted back to nitrogen gas.
How does human intervention affect nitrogen availability?
The Haber process increases nitrogen availability for crops but impacts ecosystems.
What is the rapid cycling in the sulfur cycle?
Decomposers return sulfur to soil or air as hydrogen sulfide (H₂S).
How do bacteria use sulfur?
Bacteria use sulfur in photosynthesis or respiration, converting forms of sulfur.
What are natural sources of sulfur?
Weathering of rocks releases sulfur dioxide (SO₂) and volcanic activity emits sulfur gases.
What are human sources of sulfur?
Combustion of coal, oil, and natural gas.
What are natural processes returning carbon to the atmosphere?
Forest fires and weathering of limestone.
What happens to carbon from decomposed organic matter?
It builds up in soil or sediments.
What is the universal solvent property of water?
Water dissolves a wide variety of substances due to its polarity.
What is the significance of water’s high boiling point?
It requires more energy to overcome hydrogen bonds.
Why does ice float on water?
Ice is less dense than liquid water.
What is evaporation in the water cycle?
Solar energy heats water to form vapor.
What is condensation in the water cycle?
Water vapor cools and forms droplets.
What is precipitation in the water cycle?
Water falls back to Earth as rain, snow, or hail.
What are biogeochemical cycles?
Cycles transfer nutrients between the environment and organisms.
What are the main elements in biogeochemical cycles?
Carbon (C), Hydrogen (H), Oxygen (O), Nitrogen (N), Phosphorus (P), Sulfur (S).
