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| 13460387417 | continental crust | Extends from surface of Earth down to 20-30 miles. Less dense then ocean crust (basalt). |  | 0 |
| 13460387419 | mantle | Contains most of Earth's mass. Composed of iron, magnesium, aluminum, and silicon-oxygen compounds |  | 1 |
| 13460387420 | core | Composed mostly of iron and is so hot that the outer core is molten. The inner core is under such extreme pressure that it remains solid. |  | 2 |
| 13460387422 | lithosphere | Lithosphere (crust and upper mantle) is divided into massive sections known as plates, which float and move on the asthenosphere. |  | 3 |
| 13460387423 | transform boundaries | Occur where plates slide PAST each other. |  | 4 |
| 13460387424 | San Andreas Fault | Found near the western coast of North America. Where the Pacific and North American plates move relative to each other. |  | 5 |
| 13460387425 | divergent boundaries | Occur where two plates slide APART from each other with the space that was created being filled with molten magma from below. |  | 6 |
| 13460387426 | Mid-Atlantic Ridge and Pacific Rise | Examples of oceanic divergent boundaries. |  | 7 |
| 13460387427 | East African Great Rift Valley | Examples of areas of continental divergent boundaries |  | 8 |
| 13460387428 | convergent boundaries | Occur where two plates slide TOWARD each other, commonly forming either a subduction zone or orogonic belt. |  | 9 |
| 13460387429 | subduction zone | Occurs when a denser oceanic plate moves underneath (subducts) a less-dense continental plate. e.g. Cascade Mountain range (includes Mount Saint Helens) |  | 10 |
| 13460387430 | island arc | A curved chain of volcanic islands created when two oceanic plates converge. e.g. Japan and the Aleutian Islands in Alaska |  | 11 |
| 13460387432 | earthquakes | Caused by friction and stress buildup from the sliding plates, a common feature along transform boundaries. e.g. Haiti Earthquake 2010 |  | 12 |
| 13460387433 | seismic waves | energy released in the form of vibrations when there is abrupt movement on an existing fault; they move in all directions through the surround rock |  | 13 |
| 13460387436 | What do volcano eruptions do to our atmosphere? | -Release CO2, SO2, HCl -debris and particulates can block sunlight, making a cooler climate | 14 | |
| 13460387437 | Factors that affect the amount of solar energy at the surface of the Earth: | -Earth's rotation (once every 24 hours) -tilt of Earth's axis (23.5 degrees) -revolution around the sun (once per year) -closest to sun in winter, furthest in summer |  | 15 |
| 13460387438 | O Horizon | Surface litter: leaves and partially decomposed organic debris. Thick in deciduous forests, thin in the tundra. |  | 16 |
| 13460387439 | A Horizon | Topsoil: organic matter (humus), living organisms, inorganic minerals. Topsoil is very thick in grasslands. | | 17 |
| 13460387440 | E Horizon | Zone of leaching: dissolved and suspended materials move downward. In-between A and B horizon. | | 18 |
| 13460387441 | B Horizon | Subsoil: tends to be yellowish in color due to the accumulation of Fe, Al, humic compounds, and clay leached down from A and E horizons. Can be rich in nutrients in areas with lots of rainwater. | | 19 |
| 13460387442 | C Horizon | Weathered parent material: partially broken-down inorganic minerals |  | 20 |
| 13460387444 | clay | -very fine particles that compact easily -low permeability to water, thus upper layers become waterlogged |  | 21 |
| 13460387445 | gravel | -coarse particles -consists of rock fragments | | 22 |
| 13460387446 | loam | -about equal mixtures of clay, sand, silt, and humus -rich in nutrients that holds water but does not become waterlogged |  | 23 |
| 13460387447 | sand | -coarser than silt and water flows through too quickly for most crops -good for crops and plants requiring low amounts of water | | 24 |
| 13460387448 | silt | -sedimentary material consisting of very fine particles between the size of sand and clay -easily transported by water | | 25 |
| 13460387449 | waterlogging | saturation of soil with water resulting in a rise of the water table |  | 26 |
| 13460387450 | problems of waterlogging | salty water envelops deep roots killing plants; lowers productivity; eventual destruction of plant life | 27 | |
| 13460387451 | salinization | a soil degradation process caused by repeated annual application of irrigation water in dry climates, which leads to the gradual accumulation of salts in the upper soil layers |  | 28 |
| 13460387452 | problems of salinization | stunted crop growth; lower yield; eventual destruction of plant life | 29 | |
| 13460387453 | solutions of salinization | take land out of production for a while; install drainage pipes; flush soil with freshwater; planted halophytes (salt-loving plants) like barley, cotton, sugar, or wheat | 30 | |
| 13460387454 | desertification | occurs when the productive potential of soil, especially on arid or semiarid land, falls by 10% or more because of a combination of prolonged drought and human activities that reduce or degrade topsoil |  | 31 |
| 13460387455 | problems of desertification | loss of native vegetation; increased wind erosion; salinization; drop in water table; reduced surface water supply | 32 | |
| 13460387456 | solutions of desertification | reduce overgrazing; reduce deforestation; reduce destructive forms of planting, irrigation, and mining; plant trees and grasses to hold soil | 33 | |
| 13460387457 | Soil erosion | is the movement of soil components, especially surface litter and topsoil, from one place to another by the actions of wind and water |  | 34 |
| 13460387458 | What is most harmful human activity? | Agriculture has a greater harmful environmental impact than any other human activity | 35 | |
| 13460387459 | igneous | formed by cooling and classified by their silica content. -majority of rocks in Earth's crust -Broken down by weathering and water transport. e.g. granite and basalt |  | 36 |
| 13460387460 | metamorphic | formed by intense heat and pressure e.g. diamond, marble asbestos, slate, anthracite coal | | 37 |
| 13460387461 | sedimentary | formed by piling and cementing of various materials over time in low-lying areas. Fossils form only in this e.g. conglomerate, breccia, sandstone | | 38 |
| 13460387462 | Nitrogen (N2) | Deposits on Earth through nitrogen fixation and reactions involving lightning and subsequent precipitation. Returns to the atmosphere through combustion of biomass and denitrification. | 39 | |
| 13460387463 | Oxygen (O2) | Molecules are produced through photosynthesis and are utilized in cellular respiration. | 40 | |
| 13460387464 | Water vapor (H2O) | Largest amounts occur near equator, over oceans, and in tropical regions. -most voluminous greenhouse gas, cannot be added or reduced | 41 | |
| 13460387465 | Carbon dioxide (CO2) | Volume has increased about 25% in the last 300 years due to the burning of fossil fuels and deforestation. Produced during cellular respiration and the decay of organic matter. It is a reactant in photosynthesis, also a major greenhouse gas. | 42 | |
| 13460387466 | Methane (CH4) | Contributes to the greenhouse effect. Since 1750, has increased about 150% due to use of fossil fuels, coal mining, landfills, rice paddies, melting permafrost, livestock, etc. -stays in atmosphere 12 years | 43 | |
| 13460387467 | Nitrogen dioxide (NO2/NOx) | Concentration increasing about 0.3% per year. Sources include burning of fossil fuels (vehicles), use of fertilizers, burning biomass, deforestation, etc. -stays in atmosphere 120 years | 44 | |
| 13460387468 | Ozone (O3) | 97% is found in the stratosphere (ozone layer). Absorbs UV radiation. Produced in the production of photochemical smog. CFC's have contributed to this layer depletion. A pollutant in the troposphere. | 45 | |
| 13460387469 | troposphere | -75% of atmosphere's mass is in the troposphere -temperature decreases with altitude -weather occurs in this zone |  | 46 |
| 13460387470 | stratosphere | -temperature increases with altitude due to absorption of heat by ozone -ozone is produced by UV radiation and lightning -contains the ozone layer | | 47 |
| 13460387471 | mesosphere | -temperature decreases with altitude -coldest layer -ice clouds occur here -meteors (shooting stars) burn up in this layer | | 48 |
| 13460387472 | thermosphere (ionosphere) | -temperature increase with height due to gamma rays, X rays, and UV radiation -molecules are converted into ions -causes Northern lights | | 49 |
| 13460387476 | albedo | is the diffuse reflectivity or reflecting power of a surface |  | 50 |
| 13460387477 | temperature inversion | stops atmospheric convection from happening in the affected area and can lead to the air becoming stiller and murky from the collection of dust and pollutants that are no longer able to be lifted from the surface. (COLD air) OVER (WARM air) |  | 51 |
| 13460387479 | Rain shadow (orographic) effect | the loss of moisture from the landscape and the resulting semiarid or arid conditions on the leeward side of high mountains -Windward= lush, green, clouds, precipitation, ocean...leedward= deserts, sinking air, dry |  | 52 |
| 13460387480 | Coriolis Effect | an effect whereby a mass moving in a rotating system experiences a force (the Coriolis force) acting perpendicular to the direction of motion and to the axis of rotation. |  | 53 |
| 13460387481 | monsoons | a seasonal prevailing wind in the region of South and Southeast Asia, blowing from the southwest between May and September and bringing rain (the wet monsoon), or from the northeast between October and April (the dry monsoon) | 54 | |
| 13460387482 | El Niño | occurs every few years when winds in the tropical Pacific Ocean weaken and change direction o Above-average warming of Pacific waters affects populations of marine species by changing the distribution of plant nutrients, hurting fishing industry o Severe flooding, storms, drought, mudslides, $ damage, human health hazards |  | 55 |
| 13460387483 | Grasshopper effect | occurs when volatile air pollutants are transported by evaporation and winds from tropical and temperate areas though the atmosphere to the earth's polar areas, where they are deposited. | 56 | |
| 13460387484 | natural sources of pollution | • dust blown by wind • pollutants from wildfires and volcanic eruptions • VOCs (volatile organic chemicals) released by some plants • Removed naturally by chemical cycles, precipitation, and gravity |  | 57 |
| 13460387485 | manmade sources of pollution | • Industry, cars, electrical plants, coal • Burning of fossil fuels | 58 | |
| 13460387486 | primary pollutants | are harmful chemicals emitted directly into the air from natural processes and human activities e.g. SOx, NOx, CO, VOCs, particulates, Lead |  | 59 |
| 13460387487 | secondary pollutants | formed by some primary pollutants reacting with one another and with the basic component of air to form new harmful chemicals e.g. O3, HNO3 (nitric acid), H2SO4 (sulfuric acid [acid rain]) |  | 60 |
| 13460387488 | Ways Air Pollution is Increased: | • Urban buildings can slow wind speed and reduce dilution and removal of pollutants • High temperatures promote the chemical reactions leading to photochemical smog formation (global warming increases smog!) • Emissions of VOCs from certain trees and plants (e.g. oak, sweet gums, poplars, and kudzu) can play a large role in photochemical smog formation • Temperature inversions | 61 | |
| 13460387489 | Industrial smog | (gray color) consists mostly of sulfur dioxide, suspended droplets of sulfuric acid, and a variety of suspended solid particles |  | 62 |
| 13460387490 | Photochemical smog | (brown color) is a mixture of primary and secondary pollutants formed under the influence of UV radiation from the sun; formation of this smog begins when exhaust from morning commuter vehicles releases large amounts of NO and VOCs into the air over a city • VOCs + NOx + heat + sunlight → ground level ozone (03) + aldehydes + other secondary pollutants |  | 63 |
| 13460387491 | Properties of Water: | • strong hydrogen bonds • high specific heat • high boiling point • needs a lot of energy to evaporate • expands when freezes | 64 | |
| 13460387496 | oligotrophic lakes | lakes that have a small supply of plant nutrients e.g. glaciers, mountains, lakes | 65 | |
| 13460387497 | eutrophic lakes | lakes that are well-nourished; have large supply of plants nutrients; are shallow with murky brown or green water |  | 66 |
| 13460387500 | turbidity | when the water is clouded by excessive algal growth or natural/human disturbances like waves, wind, currents, boats, tides, storms, etc. • can prevent sunlight from penetrating the water for photosynthetic plants |  | 67 |
| 13460387501 | intertidal zone | • area of shoreline between low and high tides • organisms must be able to avoid being swept away or crushed by waves; must deal with being immersed in high tides and left dry during low tides; must deal with changing levels of salinity |  | 68 |
| 13460387502 | wetlands (estuaries, swamps, marshes) | • soil is either permanently or seasonally saturated • most biologically diverse of all ecosystems • water can be saltwater, freshwater, or brackish • productive-high nutrient input from rivers and nearby land and rapid circulation of nutrients • ample sunlight in shallow waters • plant life includes: mangroves, cattails, cypress |  | 69 |
| 13460387503 | mangrove forests | • reduce the impacts of rising sea levels and more intense storm surges, which may become more powerful with global warming • help maintain water quality through filtration • produce food, habitats, and nursing sites • largest mangrove area is in Indonesia |  | 70 |
| 13460387504 | threats to aquatic biodiversity: | • dams and canals fragment natural biodiversity and destroy wildlife • cities and farms add pollutants and excess plant nutrients | 71 | |
| 13460387505 | trawler fishing | • drags funnel-shaped nets weighted down with heavy chains and steel plates over ocean bottoms to harvest a few species of bottom fish and shellfish • crushes organisms, buries them in sediment, exposes them to predators |  | 72 |
| 13460387506 | bycatch | the unwanted fish and other marine creatures caught during commercial fishing for a different species |  | 73 |
| 13460387507 | purse-seine fishing | • used to catch surface-dwelling species by having ships senclose on large schools of fish and throw nets. ex) tuna |  | 74 |
| 13460387508 | longlining | • putting out lines up to 80 miles long, hung with thousands of baited hooks, to catch open-ocean fish species • also bycatch (hook and kill accidentally) endangered sea turtles, dolphins, and seabirds |  | 75 |
| 13460387509 | drift-net fishing | huge fish are caught by huge drifting nets that can hang as deep as 50 feet below the surface and extend 40 miles long. This method can lead to overfishing of the desired and unwanted species. |  | 76 |
| 13460387511 | maximum sustained yield | model to project the maximum number of fish that can be harvested annually from a fish stock without causing a population drop | 77 | |
| 13460387513 | Hydrologic cycle | the movement of water in the seas, in the air, and on land, which is driven by solar energy and gravity |  | 78 |
| 13460387514 | groundwater | water held underground in the soil or in pores and crevices in rock | 79 | |
| 13460387517 | water table | top of the groundwater zone; can fall or rise depending on weather |  | 80 |
| 13460387518 | aquifers | • underground caverns and porous layers of sand, gravel, or bedrock through which groundwater flows • most recharge extremely slowly because urban development prevents water from easily penetrating the ground | | 81 |
| 13460387519 | artesian well | is a confined aquifer containing groundwater under positive pressure | | 82 |
| 13460387522 | saltwater intrusion | movement of saltwater into an aquifer, which may cause contamination | 83 | |
| 13460387523 | cone of depression | occurs in an aquifer when groundwater is pumped from a well |  | 84 |
| 13460387524 | surface runoff | precipitation that does not infiltrate the ground or return to the atmosphere by evaporation |  | 85 |
| 13460387525 | watershed or drainage basin | the land from which surface water drains into a particular river, lake, wetland, or other body of water • 70% of water is used for agriculture, 20% of water is used for industry, 10% of water is used by humans and cities | 86 | |
| 13460387526 | drought | a prolonged period in which precipitation is at least 70% lower and evaporation is higher than normal in an area that is normally not dry • dries out soils, reduces stream flows, decreases tree growth and biomass, lowers net primary productivity, reduces crop yields, and causes a shift in some biomes towards relatively dry conditions • political/legal conflicts, depression for farmers |  | 87 |
| 13460387527 | main factors causing water scarcity: | • dry climate, drought, too many people using a normally reliable supply of water, and wasteful use of water • farmers, cities, and car owners are increasingly competing for access to the world's grain and water supplies, which in turn can degrade some of the natural capital that provides these resources | 88 | |
| 13460387528 | Water Privatization: Pros | • Private companies have the money and expertise to manage water resources better and more efficiently than governments • Some private water management companies have done a good job in the past | 89 | |
| 13460387529 | Water Privatization: Cons | • Because private companies make money by delivering water, they have an incentive to sell as much a possible rather than conserving it • Because they have too little money to pay water bills, the poor will continue to be left out • Water should be a public resource | 90 | |
| 13460387530 | Withdrawing Groundwater: Advantages | • Useful for drinking and irrigation • Available year-round • Exists almost everywhere • Renewable if not overpumped or contaminated • No evaporation losses • Cheaper to extract than most surface waters | 91 | |
| 13460387531 | Withdrawing Groundwater: Disadvantages | • Aquifer depletion from overpumping • Sinking of land (subsidence) from overpumping • Aquifers polluted for decades or centuries • Saltwater intrusion into drinking water supplies near coastal areas • Reduced water flows into surface waters • Increased cost & contamination from deeper wells | 92 | |
| 13460387532 | sinkholes | large craters that form when the roof of an underground cavern collapses after being drained of the groundwater that supports it |  | 93 |
| 13460387533 | Groundwater Depletion: Solutions | • Waste less water • Subsidize water conservation • Limit number of wells • Do not grow water-intensive crops in dry areas • Raise price of water to discourage waste • Tax water pumped from wells near surface waters • Set and enforce minimum stream flow levels • Divert surface water in wet years to recharge aquifers | 94 | |
| 13460387534 | dam | • a structure built across river to control the river's water flow • ¼ of the world's damn produce about 20% of the world's electricity |  | 95 |
| 13460387535 | reservoir | an artificial lake created by the river's flow after it is dammed; behind dam |  | 96 |
| 13460387536 | Damming the Waterways: Advantages | • Provides irrigation water above and below dam • Provides water for drinking • Reservoir useful for recreation and fishing • Can produce cheap electricity (hydropower) • Reduces downstream flooding • Capture and store runoff | 97 | |
| 13460387537 | Damming the Waterways: Disadvantages | • Flooded land destroys forests or cropland and displaces people • Large losses of water through evaporation • Deprives downstream cropland and estuaries of nutrient-rich silt • Risk of failure and devastating downstream flooding • Disrupts migration and spawning of some fish • Sediments build up behind dam in reservoirs | 98 | |
| 13460387538 | Water in Saudi Arabia | • Saudi Arabia is as water-poor as it is oil-rich, so it gets about 70% of its drinking water at a high cost from the world's largest system for removing salt from seawater, located on its eastern coast • Saudi Arabia has the world's largest number of desalination plants |  | 99 |
| 13460387539 | desalination | • removes dissolved salts from ocean water of from brackish water in aquifers of lakes for domestic use -High cost and energy footprint -Produces large quantities of briny wastewater that contain lots of salt and other minerals...dumping this water into the ocean is bad | 100 | |
| 13460387544 | drip or trickle irrigation (micro irrigation) | method that saves water and fertilizer by allowing water to drip slowly to the roots of plants, either onto the soil surface or directly onto the root zone, through a network of valves, pipes, tubing, and emitters; MOST efficient method because least evaporation; 90-95% of water reaches the crops |  | 101 |
| 13460387545 | Reducing Irrigation Water Waste: Solutions | • Line canals bringing water to irrigation ditches • Irrigate at night to reduce evaporation • Monitor soil moisture to add water only when necessary • Grow several crops on each plot of land (polyculture) • Avoid growing water-thirsty crops in dry areas • Irrigate with treated urban wastewater | 102 | |
| 13460387547 | rainwater harvesting | involves running pipes from rooftops and digging channels to catch rainwater | 103 | |
| 13460387548 | Reducing wastewater: | • Fix water leaks, use water meters, raise water prices • Use waterless composting toilers • Require water conservation in water-short cities • Purify and reuse water for houses, offices, buildings | 104 | |
| 13460387549 | Sustainable water use: | • Waste less water and subsidize water conservation • Do not deplete aquifers • Preserve water quality • Protect forests, wetlands, mountain glaciers, watersheds, and other natural systems • Get agreements among regions and countries sharing surface water resources • Raise water prices • Slow population growth | 105 | |
| 13460387552 | biodiversity | is the variety of the earth's species, the genes they contain, the ecosystems in which they live, and the ecosystem processes that sustain all life | 106 | |
| 13460387556 | natural selection | occurs when some individuals of a population have genetically based traits that enhance their ability to survive and reproduce |  | 107 |
| 13460387557 | genetic resistance | the ability of one or more organisms in a population to tolerate a chemical designed to kill it (e.g. bacteria with regard to hand sanitizer) | 108 | |
| 13460387563 | generalist species | broad niches (e.g. deer) |  | 109 |
| 13460387564 | specialist species | narrow niches; more vulnerable (e.g. panda bear) |  | 110 |
| 13460387565 | indicator species | species that provide early warnings of damage to a community or an ecosystem (e.g. amphibians [because their breath through skin]) |  | 111 |
| 13460387566 | keystone species | have a large effect on the types and abundance of other species in an ecosystem (e.g. shark, bumblebee, sea otters in kelp forests) |  | 112 |
| 13460387571 | primary succession | the gradual establishment of biocommunities in a lifeless area that has NO soil or sediment | 113 | |
| 13460387572 | secondary succession | a series of communities or ecosystems with different species that evolve where there's soil |  | 114 |
| 13460387578 | coevolution | evolution in which two or more species interact and exert selective pressures on each other that can lead each species to undergo adaptations e.g. bats and insects | 115 | |
| 13460387583 | carrying capacity (K) | maximum population of a given species that a particular habitat can sustain indefinitely without being degraded |  | 116 |
| 13460387584 | exponential growth (J curve) | • growth that increases at a constant rate per unit of time • starts slowly, but accelerates as population increases |  | 117 |
| 13460387585 | logistic growth (S curve) | rapid population growth, followed by a steady decrease in population growth until the population size levels off | | 118 |
| 13460387586 | genetic drift | random changes in gene frequencies in a population that can lead to unequal reproductive success, some individuals will breed more, thus their genes will dominate the gene pool | 119 | |
| 13460387588 | founder effect | occurs when only a few individuals in a population colonize a new habitat that is geographically isolated (e.g. finches on Galapagos Islands) | 120 | |
| 13460387589 | demographic bottleneck effect | occurs when only a few individuals in a population survive catastrophic events, and then the population lacks genetic diversity |  | 121 |
| 13460387590 | density-dependent factors: | infectious disease, parasitism, predation, competition |  | 122 |
| 13460387591 | density-independent factors: | habitat destruction, pollution, temperature change |  | 123 |
| 13460387595 | National Wildlife Refuges | areas that have been set aside for the protection of threatened or endangered species | 124 | |
| 13460387602 | CITES | (Convention on International Trade in Endangered Species) an international treaty banning the hunting and trade of endangered species; Created a list of animals in which countries who sign are forced to protect them | 125 | |
| 13460387605 | old-growth forest | an uncut or regenerated primary forest that has not been seriously disturbed by human activities or natural disasters for 200 years or more—36% of world's forests |  | 126 |
| 13460387606 | second-growth forest | a stand of trees resulting from secondary ecological succession; these forests develop after the trees in an area have been removed by human activities (e.g. clear-cutting or fire)—60% of world's forests | 127 | |
| 13460387608 | selective-cutting | intermediate-aged or mature trees in an uneven-aged forest are cut singly or in small groups |  | 128 |
| 13460387609 | clear-cutting | removal of all trees; the most efficient way for a logging operation to harvest trees, but the most harmful; increased runoff, increased soil erosion, loss of nutrients |  | 129 |
| 13460387610 | strip-cutting | clear-cutting a strip of trees along the contour of land within a corridor narrow enough to allow natural regeneration |  | 130 |
| 13460387613 | prescribed fires | • intentional small, contained surfaces fires created to remove flammable small trees and underbrush in the highest-risk forest areas |  | 131 |
| 13460387614 | deforestation | is the temporary or permanent removal of large expanses of forest for agriculture, settlements, or other uses |  | 132 |
| 13460387617 | range-lands | are unfenced grasslands in temperate and tropical climates that supply forage, or vegetation, for grazing and browsing animals |  | 133 |
| 13460387618 | overgrazing | occurs when too many animals graze for too long and exceed the carrying capacity of range-land area; it reduces grass cover, exposes the soil to erosion by water and wind, and compacts the soil |  | 134 |
| 13460387619 | rotational grazing | cattle are confined by portable fencing to one area for a short time and then moved to a new location |  | 135 |
| 13460387620 | riparian zones | lush vegetation along streams or rivers |  | 136 |
| 13460387623 | biomes | are a major regional or global biotic community characterized by the dominant forms of plants life and the climate |  | 137 |
| 13460387625 | Coral Reefs | -warm, clear, shallow ocean habitats near land and in the tropics -disappearing because of an increase in sea temperature, pollution, dredging, and sedimentation -very sensitive to environmental changes |  | 138 |
| 13460387628 | Coal | Cheap non-renewable energy. A hard fossil fuel that is burned for electricity and releases sulfur and other toxic pollutants |  | 139 |
| 13460387629 | Petroleum | Non-renewable liquid energy. Good for mobile combustion and easily transported. |  | 140 |
| 13460387630 | Natural Gas | Mostly methane gas energy source. Burns the cleanest of all fossil fuels. | 141 | |
| 13460387631 | Nuclear Energy | the energy released during nuclear fission or fusion, especially when used to generate electricity. Waste is a major problem |  | 142 |
| 13460387632 | Biofuel Energy | when biomass is converted directly into a liquid |  | 143 |
| 13460387633 | Biomass Energy | Energy produced by burning organic matter, such as wood, food scraps, and alcohol | 144 | |
| 13460387634 | Hydroelectric Energy | The use of flowing water from waterfalls and dams to produce electricity. Costly to build, negative impacts on ecosystems, but provides huge amounts of energy |  | 145 |
| 13460387635 | Wind Energy | The energy captured by transforming the motion of air into electrical energy using a turbine | 146 | |
| 13460387636 | Solar Energy | Uses photovoltaic cells to absorb energy from the sun and transfer it to electricity. Costly but efficiency is improving | 147 | |
| 13460387637 | Geothermal Energy | Heat energy that comes from the natural radioactive decay of elements deep within Earth. | 148 | |
| 13460387638 | Hydrogen Fuel Cell | A device that uses hydrogen and oxygen to produce electricity. The byproducts are heat and water. | 149 | |
| 13460387639 | Tidal Energy | A form of renewable energy that relies on the ebb and flow of the tides to generate electricity. | 150 | |
| 13460387640 | Hybrid Car | car powered by an electric motor and an internal combustion engine. Can be recharged through applying the break | 151 | |
| 13460387643 | Indoor Air Pollutants | Asbestos, Formaldehyde, Carbon monoxide, Radon | 152 | |
| 13460387644 | Outdoor Air Pollutants | NOx, SOx, Particulate Matter, VOCs, Ozone | 153 | |
| 13460387645 | Toxic Metals | Lead, Mercury, Cadmium, Arsenic | 154 |
