AP ENVIRONMENTAL SCIENCE AP TEST REVIEW

Ionizing radiation

enough energy to dislodge electrons from atoms, forming ions; capable of causing cancer (gamma, X-rays, UV)

High Quality Energy

organized & concentrated; can perform useful work (fossil fuel & nuclear)

Low Quality Energy

disorganized, dispersed (heat in ocean or air wind, solar)

First Law of Thermodynamics

energy is neither created nor destroyed, but may be converted from one form to another (Law of Conservation of Energy)

Second Law of Thermodynamics

when energy is changed from one form to another, some useful energy is always degraded into lower quality energy, usually heat

Natural radioactive decay

unstable radioisotopes decay releasing gamma rays, alpha particles, and beta particles

Half-life

the time it takes for ½ the mass of a radioisotope to decay

Estimate of how long a radioactive isotope must be stored until it decays to a safe level

approximately 10 half-lives

Nuclear Fission

nuclei of isotopes split apart when struck by neutrons

Nuclear Fusion

two isotopes of light elements (H) forced together at high temperatures till they fuse to form a heavier nucleus (He). Process is expensive; break-even point not reached yet

Ore

a rock that contains a large enough concentration of a mineral making it profitable to mine

Organic fertilizer

slow-acting & long-lasting because the organic remains need time to be decomposed

Best solutions to energy shortage

conservation, increase efficiency, explore alternative energy options

Surface mining

cheaper and can remove more minerals; less hazardous to workers

Humus

organic, dark material remaining after decomposition by microorganisms

Leaching

removal of dissolved materials from soil by water moving downwards

Illuviation

deposit of leached material in lower soil layers (B horizon)

Loam

perfect agricultural soil with optimal portions of sand, silt, clay (40%, 40%, 20%)

Conservation

allowing the use of resources in a responsible manner

Preservation

setting aside areas and protecting them from human activities

Parts of the hydrologic cycle

evaporation, transpiration, runoff, condensation, precipitation, infiltration

Aquifer

any water-bearing layer in the ground

Cone of depression

lowering of the water table around a pumping well

Salt water intrusion

near the coast, over-pumping of groundwater causes saltwater to move into the aquifer

ENSO

El Niño Southern Oscillation, see-sawing of air pressure over the S. Pacific

During an El Niño year

trade winds weaken & warm water sloshed back to SA

During a non El Niño year

easterly trade winds and ocean currents pool warm water in the western Pacific, allowing upwelling of nutrient rich water off the west coast of South America

Effects of El Niño

upwelling decreases disrupting food chains; N U.S. has mild winters, SW U.S. has increased rainfall, less Atlantic hurricanes

Nitrogen fixing

because atmospheric N2 cannot be used directly by plants it must first be converted into ammonia (NH3) by bacteria (rhizobium)

Ammonification

decomposers convert organic waste into ammonia

Nitrification

ammonia (NH3) is converted to nitrate ions (NO3)

Assimilation

inorganic nitrogen is converted into organic molecules such as DNA/amino acids & proteins

Denitrification

bacteria convert nitrate (NO3) and nitrite (NO2) back into N2 gas

Phosphorus does not circulate as easily as nitrogen because

it does not exist as a gas, but is released by weathering of phosphate (PO4) 3 rocks

Sustainability

the ability to meet the current needs of humanity without compromising the ability of future generations to meet their needs

runoff of animal wastes, fertilizer, discharge of sewage

How excess phosphorus is added to aquatic ecosystems

Photosynthesis

plants convert atmospheric carbon (CO2) into complex carbohydrates (glucose C6H12O6)

Aerobic respiration

O2-consuming producers, consumers & decomposers break down complex organic compounds and convert C back into CO2

Largest reservoirs of C

carbonate (CO3) 2 rocks first, oceans second

Biotic and abiotic

living and nonliving components of an ecosystem

Producer/Autotroph

photosynthetic or chemosynthetic life

Fecal coliform/Enterococcus bacteria

indicator of sewage contamination

Energy flow in food webs

only 10% of the usable energy is transferred because usable energy lost as heat (second law); not all biomass is digested and absorbed; predators expend energy to catch prey

Chlorine

good= disinfection of water; bad= forms trihalomethanes

Primary succession

development of communities in a lifeless area not previously inhabited by life or those in which the soil profile is totally destroyed (lava flows); begins with lichen action

Secondary succession

life progresses where soil remains (clear-cut forest, fire)

Cogeneration

using waste heat to make electricity

Mutualism

symbiotic relationship where both partners benefit

Commensalism

symbiotic relationship where one partner benefits & the other is unaffected

Parasitism

relationship in which one partner obtains nutrients at the expense of the host

Biome

large distinct terrestrial region having similar climate, soil, plants & animals

Carrying capacity

the number of individuals that can be sustained in an area

R strategist

reproduce early in life; many small unprotected offspring

K strategist

reproduce late in life; few offspring; care for offspring

Positive feedback

when a change in some condition triggers a response that intensifies the changing condition (warmer Earth - snow melts - less sunlight is reflected & more is absorbed, therefore warmer earth)

Negative feedback

when a changing in some condition triggers a response that counteracts the changed condition (warmer earth - more ocean evaporation - more stratus clouds - less sunlight reaches the ground therefore cooler Earth)

Malthus

said human population cannot continue to increase exponentially; consequences will be war, famine & disease

Doubling time

rule of 70; 70 divided by the percent growth rate

Replacement level fertility

the number of children a couple must have to replace themselves (2.1 in developed countries)

World Population

~ 6.7 billion

U.S. Population

~ 305 million

Preindustrial stage

(demographic transition) birth & death rates high, population grows slowly, infant mortality high

Transitional stage

(demographic transition) death rate lower, better health care, population grows fast

Industrial stage

(demographic transition) decline in birth rate, population growth slows

Postindustrial stage

(demographic transition) low birth & death rates

Age structure diagrams

broad base = rapid growth; narrow base = negative growth; uniform shape = zero growth

1st, 2nd, 3rd most populated countries

China, India, U.S.

Most important thing affecting population growth

low status of women

Ways to decrease birth rate

family planning, contraception, economic rewards and penalties

Percent water on earth by type

97.5% seawater, 2.5% freshwater

Salinization of soil

in arid regions, water evaporates leaving salts behind

Ways to conserve water

agriculture= drip/trickle irrigation; industry= recycling; home= use gray water, repair leaks, low flow fixtures

Point vs. non point sources

Point, from specific location such as a pipe. Non-point, from over an area such as runoff

BOD

biological oxygen demand, amount of dissolved oxygen needed by aerobic decomposers to break down organic materials

Eutrophication

rapid algal growth caused by an excess of nitrates (NO3) and phosphates (PO4)3 in water

Hypoxia

when aquatic plants die, the BOD rises as aerobic decomposers break down the plants, the DO drops & the water cannot support life

Minamata disease

(1932-1968, Japan) mental impairments caused by methylmercury (CH3Hg) poisoning

primary air pollutant

harmful substance that is emitted directly into the atmosphere

Natural selection

organisms that possess favorable adaptations pass them onto the next generation

Particulate matter

Source: burning fossil fuels and diesel exhaust

Effect: reduces visibility & respiratory irritation

Reduction: filtering, electrostatic precipitators, alternative energy)

Nitrogen Oxides (NOx)

Source: auto exhaust

Effects: acidification of lakes, respiratory irritation, leads to smog & ozone

Equation for acid formation: NO + O2 = NO2 + H2O = HNO3

Reduction: catalytic converter

Sulfur oxides (SOx)

Source: coal burning

Effects: acid deposition, respiratory irritation, damages plants

Equation for acid formation: SO2 + O2 = SO3 + H2O = H2SO4

Reduction: scrubbers, burn low sulfur fuel)

Carbon oxides (CO and CO2)

Source: auto exhaust, incomplete combustion

Effects: CO binds to hemoglobin, reducing blood's ability to carry O2; CO2 contributes to global warming

Reduction: catalytic converter, emission testing, oxygenated fuel, mass transit

Ozone

Formation: secondary pollutant,

NO2 + uv = NO + O O + O2 = O3, with VOCs (volatile organic compounds)

Effects: respiratory irritant, plant damage

Reduction: reduce NO and VOC emissions

O3

Radon

naturally occurring colorless, odorless, radioactive gas, found in some types of soil and rock, can seep into homes and buildings, formed from the decay of uranium (U), causes lung cancer, Rn

Photochemical smog

formed by chemical reactions involving sunlight (NO, VOC, O*)

Acid deposition

caused by sulfuric and nitric acids (H2SO4, HNO3), resulting in lowered pH of surface waters

Greenhouse gases

Examples: H2O, CO2, O3, chlorofluorocarbons (CFCs), methane (CH4). Effect: they trap outgoing infrared (heat) energy, causing Earth to warm

Effects of global warming

rising sea level (thermal expansion), extreme weather, drought, famine, extinctions

Causes of ozone depletion

CFCs, methyl chloroform or trichloromethane (CHCl3), carbon tetrachloride (CCl4), halon
(haloalkanes), methyl bromide (CHBr)— all of which attack stratospheric ozone

Effects of ozone depletion

increased UV, skin cancer, cataracts, decreased plant growth

Love Canal, NY

(1950s +) chemicals buried in old canal; school and homes built over it; caused birth defects and cancer

Main component of municipal solid waste (MSW)

paper; most is landfilled

True cost / External costs

harmful environmental side effects that are not reflected in a product's price

Sanitary landfill problems and solutions

problem= leachate; solution= liner with collection system problem= methane gas; solution= collect gas and burn
problem= volume of garbage; solution= compact and reduce

Incineration advantages

volume of waste reduced by 90%, and waste heat can be used

Incineration disadvantages

toxic emissions (polyvinyl chloride, dioxins), scrubbers and electrostatic precipitators needed, ash disposal (contains heavy metals)

Best way to solve waste problem

reduce the amounts of waste at the source

Keystone species

species whose role in an ecosystem are more important than others. EG: sea otter, sea stars, grizzly bear, prairie dogs

Indicator species

species that serve as early warnings that an ecosystem is being damaged. EG: trout