AP®︎ Environmental Science: Unit 6 Flashcards

An energy resource naturally replenished at or near its rate of consumption, allowing repeated use without exhausting a fixed stock

An energy resource in finite supply that is consumed much faster than natural processes can replace it on a human timescale

Global energy consumption is increasing with population and economic development, remains dominated by fossil fuels, varies greatly per person among countries, and includes a growing renewable share

Energy-source use depends on resource availability, cost, technology, infrastructure, energy density, reliability, government policy, and environmental and public-health effects

Coal, petroleum, and natural gas formed from ancient organic matter over millions of years; finite fuels consumed far faster than they form

Recently living biomass used as firewood or charcoal, especially for cooking and heating where wood is locally accessible

Carbon-rich fuel made by heating wood with little oxygen; it is compact and burns hotter with less smoke than wood

Partially decomposed organic material from waterlogged environments that can be dried and burned as a low-quality fuel

Coal forms when buried ancient plant material undergoes heat and pressure, progressing from peat through lignite and bituminous coal to anthracite as carbon and energy content increase and moisture decreases

Lowest-grade coal; soft and brownish, with high moisture and relatively low carbon and energy content

Intermediate-to-high-grade coal with less moisture and more carbon and energy than lignite, widely used for electricity and industrial heat

Highest-grade coal; hard, dense, and highest in carbon and energy content among the three coal types

Fossil fuel composed mostly of methane; the cleanest-burning fossil fuel and used for heating, cooking, electricity, and industry

CH₄, the simplest hydrocarbon and main component of natural gas and biogas; it is a potent greenhouse gas and burns to release energy

Raw liquid fossil fuel composed of mixed hydrocarbons and refined into specialized fuels such as gasoline, diesel, and jet fuel

The separation and chemical processing of crude oil into products such as gasoline, diesel, jet fuel, heating oil, and petrochemical feedstocks

An unconventional petroleum resource consisting of clay, sand, water, and bitumen from which petroleum products can be produced

Heavy, viscous hydrocarbon mixture in tar sands that must be separated and processed or diluted

Using one fuel source to produce both electricity and useful heat by recovering thermal energy that would otherwise be wasted

The nonuniform pattern of resource deposits created by regional differences in geologic history and formation conditions

An exothermic reaction in which fuel reacts with oxygen, releasing energy; complete hydrocarbon combustion produces CO₂ and H₂O.

Burns fossil fuel to heat water into steam; the steam spins a turbine that drives a generator, converting chemical energy → thermal energy → mechanical energy → electrical energy

Removal of overburden—soil and rock—to expose shallow coal deposits, causing substantial land and habitat disturbance

Use of shafts and tunnels to reach deep coal deposits, with risks including worker hazards, subsidence, and acidic drainage

A form of surface mining that removes overburden in long strips to expose shallow horizontal coal seams, causing extensive land and habitat disturbance

A surface-mining method that blasts and removes a mountain’s summit to expose coal seams, often depositing waste rock in nearby valleys and streams

Drilling a well into porous rock beneath an impermeable layer to recover accumulated petroleum or natural gas

High-pressure water, sand, and chemicals fracture low-permeability rock so oil or gas can enter a well; it can contaminate groundwater and release VOCs

Splitting a large atomic nucleus such as U-235 into smaller nuclei, releasing heat, ionizing radiation, and additional neutrons

The fissile uranium isotope used as reactor fuel; it has a half-life of about 704 million years

A self-sustaining sequence in which neutrons released by fission cause additional nuclei to undergo fission

A long metal tube containing uranium fuel pellets; multiple rods are grouped in the reactor core

A neutron-absorbing rod inserted to slow a reactor’s chain reaction or withdrawn to increase its rate

Electricity generation in which controlled U-235 fission releases heat, heat produces steam, and steam turns a turbine connected to a generator; it is nonrenewable because uranium is finite

The spontaneous loss of energy from an unstable nucleus through the emission of particles or electromagnetic radiation

The time required for half of the radioactive nuclei currently present in a sample to decay

Hazardous solid material containing unstable isotopes that must be isolated from organisms and the environment while it remains radioactive

Human-caused warming of natural water, which lowers dissolved oxygen and can stress or kill aquatic organisms

A 1979 Pennsylvania accident in which equipment and human failures caused a partial meltdown, but containment limited the radioactive release

A 1986 reactor explosion and fire caused by design flaws and unsafe testing, producing a massive uncontained radioactive release and lasting contamination

A 2011 earthquake-and-tsunami disaster that disabled power and cooling, causing multiple meltdowns, hydrogen explosions, and land and ocean contamination

Recently living organic material used as fuel; it stores chemical energy originally captured from sunlight through photosynthesis

A fuel made from recently living organic material, including ethanol fermented from plant sugars and methane-rich biogas produced by anaerobic decomposition

An alcohol biofuel made by fermenting plant sugars and used as a substitute for or additive to gasoline

The conditional balancing of combustion CO₂ by CO₂ absorbed during regrowth; land-use change and fossil-energy inputs can prevent full life-cycle neutrality

Usable energy obtained ÷ energy required to produce the fuel; ethanol has a low EROI and therefore a relatively small net energy gain

A device that converts light energy directly into electrical energy, initially as direct current (DC)

A system that uses pumps or other equipment to collect and move solar heat in a fluid, allowing the thermal energy to be stored

A design that absorbs and uses solar heat directly without mechanical or electrical collection equipment or dedicated energy storage

Solar energy is renewable and produces no direct air pollution during operation, but output is intermittent and large installations require land and can damage or fragment habitat

Renewable electricity generation in which moving water turns a turbine connected to a generator, without burning fuel

A dam stores elevated water in a reservoir and releases it through turbines to generate electricity

Hydroelectric generation that uses or diverts a river’s natural flow with little or no water storage

Renewable energy from rising, falling, or flowing tides used to turn turbines

Thermal energy stored within Earth; in power generation, it produces vapor that spins a turbine connected to an electrical generator

A toxic, rotten-egg-smelling gas that geothermal fluids can release when brought to the surface

An electrochemical device that combines hydrogen and oxygen to produce electricity, water, and heat without directly emitting carbon dioxide

Use of moving air to generate electricity; renewable and clean during operation, but turbine blades can kill birds and bats

Reducing human energy demand through changes in behavior, technology, design, or transportation rather than merely changing energy sources

Providing the same service with less energy input; efficiency = useful energy output ÷ total energy input × 100

Appliances designed to provide the same service with less electricity or fuel, often identified by efficiency ratings or ENERGY STAR certification

Selecting and placing vegetation and landscape materials to reduce building heating, cooling, and irrigation demand

Distance traveled per unit of fuel, commonly miles per gallon; fuel consumed = distance traveled ÷ fuel economy

A vehicle propelled by an electric motor using battery-stored electricity; it has no tailpipe emissions, but generation and manufacturing still cause impacts

A vehicle combining an internal-combustion engine with an electric motor and battery to use less fuel than a comparable conventional vehicle

Shared transportation that can reduce energy use and emissions per passenger-mile when enough riders share the vehicle’s energy consumption

Designing and operating buildings to reduce energy and resource demand through orientation, insulation, sealing, shading, efficient systems, controls, and water-saving features