Water Quality Unit 1

SciConnect flashcards based on the 2026 SciOly Seasaon

biogeochemical cycles

movement of certain chemical elements through various forms (living AND nonliving)

runoff

water from precipitate and snow melt that doesn’t melt into the ground

transpiration

plants absorb water via roots, some evaporate into the atmosphere through stomata

evapotranspiration (ET)

total liquid water loss from surface to the atmosphere (evaporation + transpiration)

cellular respiration

living organisms convert glucose and oxygen in energy (ATP), H₂O, CO₂

Equation: C₆H₁₂O₆ —> 6CO₂ + 6H₂O + ATP

infiltration

water on the surface soaks into the ground

percolation

movement of water through porous material

porosity

measure of empty spaces within a material. indicates how much liquid a material holds

sublimation (rare)

ice —> water vapor, can occur w/ unique conditions like some dry winds

electronegativity

measure of an atom’s ability to attract electrons

polarity

when one part of the molecule has a slightly negative charge and another part has a slightly positive charge

• don’t share their electrons evenly

hydrogen bond

a strong type of bond between molecules that can occur when the polar molecules contain hydrogen atoms

cohesion

water’s tendency to stick to itself (caused by H₂O’s polar and hydrogen bonding & causes water tension)

adhesion

tendency to stick to other substances (caused by H₂O’s polar and hydrogen bonding)

diffusion

molecules move from high to low concentrations

sources of carbon

1. atmosphere (CO₂ & CH₄ (methane))

2. land

3. earth’s interior (fossil fuels & volcano)

4. ocean (carbonic acid)

5. human (burning & deforestation) and organisms (photosynthesis & cell respiration)

nitrogen cycle

the process by which nitrogen moves through the atmosphere, soil, and living organisms; driven by bacteria, limiting nutrient

non usable forms

nitrogen gas (N₂), nitrites (NO₂)

usable forms of nitrogen

ammonia (NH₃), ammonium (NH₄⁺), & nitrates (NO₃)

nitrogen fixation

atmospheric nitrogen can’t be used by plants —> ammonia (by bacteria) and sometimes nitrates; lightning heats air very hot & allows it to react —> nitrogen oxides (add water) —> nitrates

nitrification

ammonia —> nitrite —> nitrate

assimilation

inorganic nitrogen —> organic molecules (adding carbon)

ammonification

decomposes convert org. waste to ammonia (NH₃) or ammonium (NH₄+)

denitrification

bacteria convert nitrate or nitrite to atmospheric nitrogen (N₂)

phosphorus

not found in gas form

sedimentary rocks

most common source of phosphorus

inorganic phosphate

rocks

organic phosphate

DNA components

biological assimilation

plants and microorganisms take up inorganic sulfates and convert them into organic sulfur compounds

sulfate reduction

anaerobic microorganisms reduce sulfates to sulfides, marine sediments

decomposition

decomposers break down organic matter releasing hydrogen sulfide (H₂S)

sulfide oxidation

chemoautotrophs and sulfur-oxidizing microbes use hydrogen sulfide or elemental sulfur as energy source, converting it back to sulfates