the time it takes for ½ the mass of a radioactive isotope to decay.
8
New cards
Estimate of how long a radioactive isotope must be stored until it decays to a safe level
A radioactive isotope must be stored for approximately 10 half-lives until it decays to a safe level.
9
New cards
Nuclear Fission
nuclei of isotopes split apart when struck by neutrons
10
New cards
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 has not yet been reached. Happens in the Sun.
11
New cards
Ore
a rock that contains a large enough concentration of a mineral making it profitable to mine.
12
New cards
Mineral Reserve
identified deposits currently profitable to extract.
13
New cards
Best Solution To Energy Shortage
conservation, increase efficiency, explore alternative energy options.
14
New cards
Organic Fertilizer
slow-acting and long lasting because the organic remains need time to be deposited.
15
New cards
Surface Mining
cheaper and can remove more minerals, less hazardous to workers
16
New cards
Humus
organic, dark material remaining after decomposition by microorganisms.
17
New cards
Leaching
removal of dissolved materials from soil by water moving downwards
18
New cards
Illuviation
deposit of leached material in lower soil layers (B Horizons)
19
New cards
Loam
perfect agricultural soil with optimal portions of sand, silt, clay (40%, 40%, 20%)
in arid regions, water evaporates leaving salts behind. (ex: Fertile Cresent in southwestern US)
22
New cards
Conservation
allowing the use of resources in a responsible manner.
23
New cards
Preservation
setting aside areas and protecting them from human activities.
24
New cards
Water Logging
water completely saturates soil and starves plant roots of oxygen, rots roots.
25
New cards
Hydrologic Cycle Components
evaporation, transpiration, runoff, condensation, perception and infiltration.
26
New cards
Watershed
all of the land that drains into a body of water
27
New cards
Aquifer
underground layers of porous rock allow water to move slowly
28
New cards
Cone of Depression
lowering of the water table around a pumping well
29
New cards
Salt Water Intrusion:
near the coast, overpumping of groundwater causes saltwater to move into the aquifer.
30
New cards
ENSO: El Nino Southern Oscillation
See-Sawing of air pressure over the South Pacific
31
New cards
During an El Nino year
trade winds weaken and warm water sloshed back towards South America.Diminished fisheries off South America, drought in western Pacific, increased precipitation in southwestern North America, fewer Atlantic hurricanes
32
New cards
Effects of El Nino
Upwelling decreases disrupting food chains; Northern US has mild winters and Sothwest US has increased rainfall, less Atlantic Hurricanes
33
New cards
La Nina
Normal" year, easterly trade winds and ocean current pool warm water in the western Pacific, allowing upwelling of nutrient rich water off the West Coast of South America
34
New cards
Nitrogen Fixation
because atmospheric nitrogen cannot be used directly by plants, it first must be converted into ammonia by bacteria
35
New cards
Ammonificum
decomposers convert organic waste to ammonia
36
New cards
Nitrification
ammonia is concerted to Nitrate ion (NO-1)
37
New cards
Assimilation
inorganic N in converted into organic molecules such as DNA/amino acids and proteins.
38
New cards
Deniitrification
bacteria convert nitrate (NO3)-1 and nitrite (NO2)-1 back into N2 gas.
39
New cards
Phosphorous 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.
40
New cards
Phosphorous Cycle is: (speed-wise)
a slow cycle and not atmospheric
41
New cards
Phosphorous is a major limiting nutrient
in the growth of plants
42
New cards
How phosphorous is added to aquatic ecosystems
runoff of animal wastes, fertilizer, discharge of sewage.
43
New cards
Sustainability
the ability to meet the current needs of humanity with compromising the ability of future generations to meet their needs
44
New cards
Photosynthesis
plants convert CO2 (atmospheric carbon) into complex carbohydrates (sugars) (glucose C6H12O6)
45
New cards
Aerobic Respiration
Oxygen (O2) consuming producers, consumers and decomposers break down complex organic compounds and convert Carbon (C ) back into CO2
46
New cards
Largest Reservoirs of Carbon (C)
carbonate (CO3)2- rocks first, oceans second.
47
New cards
Biotic
the living component of an ecosystem
48
New cards
Abiotic
non-living component of an ecosystem
49
New cards
Producer/Autotroph
organisms that make their own food—photosynthetic or chemosynthetic life
only 10% of the usable energy is transferred to the next trophic level: REASON: because usable energy is lost as heat. (Second law of thermodynamics): not all biomass is digested and absorbed; predators expend energy to catch prey
52
New cards
Succession
in ecology, the gradual colonization of a habitat after an environmental disturbance (ex fire, flood), usually by a series of species
53
New cards
Primary Succession
development of communities in a lifeless area not recently inhabited by life (ex. retreating glacier) or those in which the soil profile is completely destroyed (lava flows): begin with lichen action
54
New cards
Secondary Succession
life progresses where soil remains (clear cut forest, vacant lot, old farm or fire)
55
New cards
Climax Community
the stable, final community that develops from ecological succession
56
New cards
Symbiosis
occurs when members of two different species live in close physical contact with each other.
57
New cards
Mutualism
symbiotic relationship where both organisms benefit
58
New cards
Commensalism
symbiotic relationship in which one organism benefits and the other organism is unaffected.
59
New cards
Parasitism
relationship in which one organism (the parasite) obtains nutrients at the expense of the host.
60
New cards
Biomes
large distinct terrestrial region having similar climate, soil, plants and animals
61
New cards
Carrying Capacity
the number of individuals the can be sustained in an area
62
New cards
R strategist
reproductive strategy in which organisms reproduce early; bear many small; unprotected offspring (ex. insects, mice)
63
New cards
K strategist
reproduce late in life; few offspring; care for offspring
64
New cards
Positive Feedback
when a change in some conditions triggers a response that intensifies the changing condition (warmer Earth—snow melts—less sunlight is reflected and more is absorbed, therefore a warmer Earth)
65
New cards
Negative Feedback
when a change 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 a cooler Earth)
66
New cards
Natural Selection
organisms that possess favorable adaptations (traits) and pass them onto the next generation. These organisms have higher reproductive success.
67
New cards
Exotic Species/Invasive Species
non-Native species to an area; often thrive and disrupt the ecosystem balance; examples African Honeybee; Fire Ant, Zebra Mussel, Purple Loosestrife.
68
New cards
Doubling Time: (Rule of 70):
doubling time equals 70 divided by the percent growth rate. For example, if a population is growing at 5% annually, it doubles in 14 years; 70/5 -14 years.the number of children a couple must have to replace themselves (averages 2.1 in developed nations, 2.7 in less developed nations)
69
New cards
Replacement Level Fertility
the number of children a couple must have to replace themselves (averages 2.1 in developed nations, 2.7 in less developed nations)
70
New cards
World Population
7.5 Billion
71
New cards
U. S. Population
321 Million
72
New cards
Preindustrial Stage
birth and death rates high, population grows slowly, infant mortality high
73
New cards
Transitional Stage
death rate (infant mortality) lower, birth rates remain high, better health care, population grows fast
family planning; contraception, economic rewards and penalties
80
New cards
Composition of Water on Earth
97.5% Seawater; 2.5% freshwater
81
New cards
Ways to conserve water
drip/trickle irrigation; Industry: recycling; Home: use gray water, repair leaks, low flow fixtures, different types of yard (zeroscape not planting Kentucky Blue grass), time of day watering...
82
New cards
Gray Water
Any wastewater from a house EXCEPT TOILIET WATER; (dish water, shower water...) this water can be used for irrigation water...
source from specific location such as pipe or smokestack
85
New cards
Non-point Source: (Area/Dispersed Source)
source spread over an area such as agricultural/feedlot runoff, urban runoff, and traffic runoff
86
New cards
Primary Sewage Treatment
first step of sewage treatment; eliminates most particulate material from raw sewage using grates, screens, and gravity (settling).
87
New cards
Secondary Sewage Treatment
second step of sewage treatment; bacteria breakdown organic waste; aeration accelerates the process.
88
New cards
BOD: (Biological Oxygen Demand)
amount of dissolved oxygen needed by aerobic decomposers to break down organic materials
89
New cards
Eutrophication
rapid algal growth (algal bloom) caused by an excess of nitrogen and phosphorous, blocks sunlight, causing the death/decomposition of aquatic plants, decreasing dissolved oxygen (DO), suffocating fish. The rapid growth is caused by an excess nitrates (NO3)-1, and phosphates (PO4)3- in water.
90
New cards
Hypoxia
water with very low dissolved oxygen levels, the end result is eutrophication. The BOD rises as aerobic decomposers breakdown the plants , the dissolved oxygen (DO) drops and the water cannot support life.
91
New cards
Fecal coliform (Enterrococus bacteria
Coccus (round shaped bacteria); indicator of sewage contamination (Happens over the summer at Chatfield or Cherry Creek Reservoir once in a while.)
92
New cards
Chlorine
Good: disinfection of water; Bad: forms trihalomethanes (this group of compounds are byproducts of chlorination and are known carcinogens)
93
New cards
Minamata Disease
(1932-1968 Japan) mental impairments caused by methylmercury (CH3Hg)+1 poisoning
94
New cards
CAFÉ standards
Corporate Average Fuel Economy : standards enacted into law in 1975, established fuel efficiency standards for passenger cars and light trucks. The fuel economy ratings fro a manufacture's entire line of passenger cars must currently average at least 27.6 mpg for the manufacturer to comply with the standard.
95
New cards
Primary Air Pollutants
produced by human and nature (CO, CO2, SOx NOx,hydrocarbons, particulates)
96
New cards
Secondary Pollutants
formed by reaction of primary pollutants.
97
New cards
Particulate Matter
**a. Source:** burning fossil fuels and diesel exhaust
**b. Effects:** reduces visibility and respiratory irritation
**c. Reduction:** filtering, electrostatic precipitators, alternative energy
98
New cards
Nitrogen Oxides: (NOx)
**a. Source :** auto exhaust
**b. Effects:** acidification of lakes, respiratory irritation, leads to smog and ozone
**c. Equation For Acid Formation:** NO + O2 🡪 NO2 + H2O 🡪 HNO3
\ **d. Reduction:** Catalytic Converter
99
New cards
Carbon Dioxide (CO2)
\ **a. Source:** combustion of fossil fuels
**b. Effects:** greenhouse gas—contributes to global warming
**c. Reduction:** accomplished by increased fuel efficiency (gas mileage) mass transit (reduction)