APES Unit 6

Radioactive decay

(half-life is a measure of time for half of an atomic nucleus),(decay into another atom emitting radiation), (ten half-lives generally means safe)

Which country produces the most coal?

China

Which country uses the most coal?

China

Which country uses the most hydropower?

China

Which country uses the most solar power?

China

Which country uses the most wind power?

China

How is coal formed?

Coal is formed when dead plant matter decays into peat and is converted into coal by the heat and pressure of deep burial over millions of years.

What is the difference between the three types of solar energy?

Photovoltic- transforms sunlight directly into electricty Active solar- uses mechanical and electric equipment to transfer solar heated liqiud to transfor heat or create eletricity Passive solar-heat is directly absored from the sun without mechaincal or elerictal equipment

Pros and Cons active solar

Pros -generates electricity or heat -large and small application Cons -expensive -requires maintenance -solar farms may negatively impact fragile desert ecosystem -require high solar intensity to maximize energy

Pros and Cons of passive solar

Pros -relatively inexpensive and low maintence Cons -some aspects are diffucult to implement retroactively -energy cannot be collected or stored

Pros and Cons of wind energy

pros -renewable -clean -allows for multiple use lands cons -birds and bats can be killed by turbines -maintence required -location must have constant wind to provide constant power(need backup power source)

Reasons people are switching to renewable energy.

- ethics, tax cuts, subsides

Geothermal

-(0.2% of Us total Energy) - renewable - heating, electricty

Solar

-(1.0% of Us total Energy) - renewable - heating, energy

Coal

-(11.3% of Us total Energy) - nonrenewable -electricty, manufactoring

Hydropower

-(2.5% of Us total Energy) - renewable - elecrity

Wind

-(2.7% of Us total Energy) - renewable -electricity

Natural Gas

-(32% of Us totoal Energy) - nonrenewable - heating, electricty, manufacturing, transportation

Petroleum

-(36.7% of Us total Energy) - nonrenewable - transportation, manufacturing, electricty

Biomass

-(5.0% of Us total Energy) - renewable - heating,elecrity, transportation

Nuclear (from uranium)

-(8.4% of Us total Energy) -nonrenewable -electricity

How hydrofuel cells work

-hydrofuel h2 is added to the cell -this can be in liquid or gas form -in the firs reaction layer, h2 molecules. are split into protons and electrons -protons and electrons take different paths. -protons move across the membrane -electrons are free to take an alternative route, creating a flow of electric current -in second reaction layer, o2 molecules are split. and combine with protons and electrons (water vapor is the only emission)

What are the dangers of fracking?

-well can contaminate water/destroy habitat -If a pipe is not lined properly, may contaminate water - fracking fluid contains volatile organic compounds -natural gas may leak out of the well *it may cause earthquakes

Which country uses the most biomass energy?

Ethiopia

In many parts of the United States, homeowners use a significant portion of their energy budget to heat their home in the winter. It has been determined that lowering a thermostat by 3°F in the winter can reduce the energy costs by about 10 percent in many homes. An individual homeowner lowers their thermostat by 3 degrees exactly halfway through the billing period. For the month that the thermostat was lowered, the heating bill was $95. How much money did the family save in the month in which they lowered the thermostat setting halfway through the billing period?

If the family paid $95 for the month, for half of the month they paid 1x and for the other half they paid .9x (a savings of 10% ). $95÷1.9x , x=$50 . The bill should have been $50 for each half of the month, but in the second half the bill was only $45 ($95−$50=$45) .

Cogenration

One way industries try to reduce waste is by using byproducts of a reaction

Precent Change Formula

Percent % = (number / total) x 100 Percent Increase = [(final - initial)/ initial] x 100

Which country produces the most petroleum?

Saudi Arabia

Which country produces the most natural gas?

The USA

Which country uses the most geothermal energy?

USA

Which country uses the most natural gas?

USA

Which country uses the most nuclear power?

USA

Which country uses the most petroleum?

USA

How does fracking work?

Well is made (lined with clay), pipe inserted, fracking. fluid inserted, gas flows out

Rank the types of coal from least to most carbon content.

anthracite, bituminous coal, sub-bituminous coal, and lignite

How are fossil fuels formed?

fossil fuels are formed underground over millions of years from the remains of dead organisms

How is petroleum formed?

from the remains of ocean dwelling phytoplankton that died 50-150 million years ago

What are the three types of coal?

lignite, bituminous, anthracite

How is natural gas formed?

natural gas is a product of decomposed organic matter, typically from ancient marine microorganisms, deposited over the past 550 million years.

Pros and Cons of biofuels

pros -combustion is carbon neutral (modren carbon vs fossil fuel carbon) -potentially renewable -can be produced domestically cons -net energy is low -harvesting crops for ethanol has the potenial for: increased use of fossil fuels in harvest, increased deforestation, reduction in fertility of land

Pros and Cons of biomass

pros -easily accesible -relatively inexpensive -used for heating and cooking cons -air polluants:co2,co,nitrogen oxides,particules,volatile organic compounds -typically burned indoors intensifying health effects -overharvesting of trees

Pros and Cons of photovoltaic cells

pros -generation of electricity -can reduce habitat destruction depending on installation placement -large and small scale applications =off the grid electricity cons -used limited by the availability of sunlight -limited lifespan of renewable PV cells -expensive -solar farms may negatively impact fragile desert ecosystem

Pros and cons of nuclear power

pros -low NoCH4/CO2 emissions -high power output -low cost (after initial cost) -no mining for fossil fuels -no primary/secondary air pollutants Cons -long-lived hazardous waste/nuclear accidents -thermal pollution -very high initial cost -mining for construction and uranium -nonrenewable

Pros and Cons of hydroelectricity

pros -no air pollution -no waste -relatively inexpensive electricity generation -additional services provided by reservoir cons -flooding of land for reservoir -disruption to flow rates of river -high construction cost for dams -most viable site already in use

Pros and Cons of hydrofuel cells

pros -no co2 emissions (if produced from water) -elecricty is more efficient than internal cumbustion cons -technology is expensive -producing hydrofuels from fossil fuels is not clean

Pros and Cons of geothermal energy

pros -no cumbustion=no Co2 emissions -not dependent on variable weather factors, like wind and solar cons -accessibility (at reasonalbe cost) is limited -release of gases during drilling and processing=hydrogen sulfide -short-term depletion of heat possible -impact on ground water levels

How is peat formed?

when organic matter is not fully decomposed because of acidic and/or anaerobic conditions in waterlogged soils