Chemistry and the Environment (word)
In this method, contaminants are solidified with an electric current, resulting to contaminant immobilization. This method can immobilize pollutants for as long as 10,000 years. However, this process uses a large amount of electricity, thus it is very costly.
Vitrification
As the surface rocks were completely oxidized, ____ levels in the atmosphere began to _____.
oxygen; rise
Inorganic sand, silt, clay and organic components interact to produce large soil features such as _____
peds, profiles, pedons, and landscapes
As higher life forms emerged on the planet, ____ helped the production of atmospheric O2 while ____ consumed it, until the O2 levels stabilized to what we know today.
plants ; animals
The bonds between oxygen and each hydrogen atom are _____ bonds with a _____% partial ionic character.
polar ; 40
The bonds between oxygen and each hydrogen atom are_____ with a 40% partial ionic character. T
polar bonds
The presence of these life forms in water are affected to a significant extent by the presence of _____.
pollutants
Usually, _____in water cause the reduction in population of both plant and animal lives.
pollutants
If water contracted as other compounds, it would _____(as ice) and destroy life.
sink
a low vapor pressure results to a ____evaporation of the liquid and a _____number of vapor molecules, resulting to a ___boiling point.
slow, fewer , higher
The only disadvantage of hard water is that it doesn't dissolve with _____.
soap
On the other hand, addition of _____, like salts and sugars, _____the vapor pressure.
solutes, decrease
(Water) contains ____ that hold two hydrogen atoms and one oxygen atom together.
strong covalent bonds
Since the young planet Earth did not yet have a magnetic field, ______ from the Sun blew this early atmosphere away.
strong solar winds
_____ acid and salts of sulfuric acid also contribute to water acidity.
sulfuric
Certain organisms provide the natural tendency of ____ water to clean itself
surface
As the _____ were completely oxidized, oxygen levels in the atmosphere began to rise.
surface rocks
Cohesion
- this property can be attributed to hydrogen bonds holding together water molecules for liquids. It plays an important role for water transport in plants and accounts for the high surface tension of water.
Excellent Solvent
- this property is important for many biological processes use water as a dispersing medium for the delivery of nutrients and waste products. It can be accounted from water's high dielectric strength.
High Specific Heat Capacity
- this property is of important consideration when water is used as a medium of heat transfer. A considerable amount of energy is needed to raise the temperature of water, therefore making it an effective cooling agent.
Expansion
-water is one of the only compounds that expands when it freezes. If it contracted as other compounds, it would sink (as ice) and destroy life.
The pH level of bodies of water are usually maintained between_____
6 and 9.5
_____% of our planet's surface is covered with water.
75
The inorganic components of soils represent more than ____% of the solid components. These include both primary and secondary minerals.
90
about ____% of that water is present in the seas and oceans, making it unusable for drinking, agriculture, and industrial purposes.
97
This method is effective on some non-volatile compounds. It involves the enhancement of naturally occurring microorganisms by boosting their numbers and activity. These microbes assist in the degradation of soil contaminants. However, it has a long-term timeframe.
Biodegradation
______ of soil humus is the maximum number of moles of proton charge dissociable from unit mass of solid-phase humus under given conditions of temperature, pressure, and aqueous solution composition, including the humus concentration.
CEC (Cation Exchange Capacity)
It plays an important role for water transport in plants and accounts for the high surface tension of water.
Cohesion
_____ is a fundamental factor for underwater life
Dissolved oxygen (DO)
____ is removed the atmosphere through the nitrogen cycle and becomes part of living organisms. ]
Nitrogen
_____ can move over large distances due to the large space available below the earth's surface.
Ground water
Since liquid water has a small bond angle, the molecules can be packed together more tightly, therefore having a higher coordination number.
Ice has a smaller coordination number, making it less dense than liquid water. As a result, ice floats.
_____ methods are used at the contamination site itself. Here, the soil does not need to be excavated and therefore exposure pathways are minimized.
In situ
______ compose the solid portion of soil.
Inorganic sand, silt, clay and organic
_____, on the other hand, originate in areas where the top soil is thin and limestone formations are sparse and absent.
Soft waters
In this method, the contaminated soil is excavated and spread over land for natural processes such as biodegradation to occur to decontaminate the soil. The soil pH is then adjusted to 7.0 to immobilize heavy metals and enhance the activity of soil microbes.
Land Treatment
This method involves leaching the soil with water and a surfactant. The surfactant lowers the surface tension of water, thus removing the contaminants. The leachate, found downstream of the site, is then collected for treatment or disposal. The method is not commonly practiced due to large volumes of waste water produced and with disposal costs high.
Leaching
As higher life forms emerged on the planet, plants helped the production of atmospheric ____while animals consumed it, until the ____levels stabilized to what we know today.
O2
Osmosis and Capillary Action - these properties enable water to climb tree tops. ____ allows plants to feed and for marine creatures to absorb fresh water in increasing salt-water environments.
Osmosis
____ is the most prevalent element in the Earth's crust and in soils.
Oxygen
This method makes use of plants to decontaminate soils and water. It is effective with several inorganic and organic chemicals. Common examples would be sunflowers used to absorb uranium, certain ferns used to absorb arsenic and clovers which take up oil.
Phytoremediation
_____ can also be termed as an increase in the concentration of naturally occurring substances. The sources of these substances are called _____.
Pollution , natural sources
_____is a good natural resource of fresh water.
Precipitation
____ of weak acids and strong bases act as buffers to resist a drop in pH resulting from acid addition.
Salts
mixture of plant and animal residues in different stages of decomposition, substances synthesized microbiologically and/or chemically from the breakdown products, and the bodies of live and dead microorganisms and their decomposing remains.
Soil organic matter (SOM)
Since the young planet Earth did not yet have a magnetic field, strong solar winds from the ____ blew this early atmosphere away.
Sun
air
The thick mixture of gases that comprise the atmosphere
In this method, the excavated soil is subjected to extreme heat using a thermal incinerator. The high temperature breaks down the pollutants, and the volatiles released are then collected and are either burned or recovered as solvents. However, this is a costly method.
Thermal Treatment
This low-cost method causes mechanical drawing or air venting through the soil. A draft fan is injected which causes an air flow through the soil, via a slotted or screened pipe, so that air can flow while preventing the entrainment of soil particles. This method removes compounds which are resistant to biodegradation. However, its application is only limited to volatile organic carbons.
Volatilization
Salts of weak acids and strong bases act as buffers to resist a drop in pH resulting from ____.
acid addition
Naturally, the alkalinity of waters can be attributed to the salts of weak _____, though weak or strong bases can contribute.
acids
Another problem is that ground water does not have access to ___, rendering the oxidation of pollutants into harmless products impossible.
air
The thick mixture of gases that comprise the atmosphere is collectively called as ____.
air
Layers of soil and rocks that hold or bear water are called ____.
aquifers
Salts of weak acids and strong bases act as _____ to resist a drop in pH resulting from acid addition.
buffers
Just like oxygen, it is continually exchanged between the atmosphere and biosphere through photosynthesis and respiration.
carbon dioxide
Precipitation from clouds created oceans, with these oceans simultaneously absorbing atmospheric _____.
carbon dioxide
Most of the first produced oxygen were released as a by-product by organisms known as ______ which were to the first to undergo photosynthesis.
cyanobacteria
At higher temperatures, the molecules have more ____, therefore, making it easier for molecules to vaporize from their liquid state, ____the molecules in the vapor state.
energy, increasing
However, beginning in the 1970s and surely in the 1990s, concerns arose about the impact of inorganic and organic contaminants in water and soil to plant, animal and human health, leading to the birth of _____.
environmental soil chemistry
____ can be accounted from water's high dielectric strength
excellent solvent
The remaining 3% is ____water, with 75% of it found in the polar ice caps, glaciers, and in underground water. The usable fresh water comes down from two sources: _____.
fresh , surface water & ground water
Ground water is the part of precipitation that seeps into the ground due to ____, filling pores between soil particles and rocks.
gravity
For many towns and cities, _____ is the only source of drinking water.
ground water
Soil chemistry initially focused on the chemical reactions in soils that affect plant's _____
growth and nutrition.
High Specific Heat Capacity - this property is of important consideration when water is used as a medium of ____
heat transfer.
When the vapor pressure is ___, evaporation of the liquid is ____, and a _____number of vapor molecules exist. As a result, the boiling point is ____.
high, rapid, high , low
Cohesion - this property can be attributed to _____ holding together water molecules for liquids. It plays an important role for water transport in plants and accounts for the____ of water.
hydrogen bonds, high surface tension
The____ cycle continuously replenishes a small fraction of the usable surface water. The water cycle involves the ____ of water from different sources, the _____ of water vapor to form clouds, and the _____ of water to the earth through precipitation.
hydrological (or water), evaporation, condensation, return
chemical species tend to predominate this layer
hypolimnion
Two techniques are used for decontamination of soils: the ______ techniques.
in situ and non-in-situ
An increase in temperature results to an _____ in vapor pressure.
increase
An increase in water temperature results to an ____ of metabolic rates of aquatic organisms.
increase
This can cause an organism, e.g. fish, to use more energy just to survive, preventing fish from performing some of its activities necessary to survive, like finding food and escaping natural predators
increase in water temperature resulting to an increase of metabolic rates of aquatic organisms
Since the young planet Earth did not yet have a ______, strong solar winds from the Sun blew this early atmosphere away.
magnetic field
Osmosis allows plants to feed and for ____creatures to absorb fresh water in increasing salt-water environments.
marine
Nitrogen is removed the atmosphere through the nitrogen cycle and becomes part of living organisms. The cycle undergoes a process called _____ wherein atmospheric N2 is reduced to form ammonia.
nitrogen fixation
Through the photochemical dissociation of water vapor by strong ultraviolet radiation, _____ was formed in the atmosphere.
oxygen
The _____ released during photosynthesis was then used in oxidation of metals like _____.
oxygen, iron
The part of precipitation, which "runs off" to form streams and rivers, is called _____.
surface water
two types of fresh water pollution:
surface water pollution and ground water pollution
Some of the factors that affect vapor pressure are _____and _____.
temperature and impurities
Distinct layers within non-flowing bodies of water (such as lakes) form due to _____ between the layers.
temperature difference
During warm seasons, the surface layer (or epilimnion) of a body of water is constantly exposed to solar radiation. Its higher temperature results to a lower density, making it float over the bottom layer (or hypolimnion). This phenomenon is called _____.
thermal stratification
a phenomenon wherein a significant temperature difference exists between two layers of a body of water, in which they do not mix, but they behave independently and have different chemical and biological properties.
thermal stratification
this layer contains higher levels of dissolved oxygen
thermocline
Osmosis and Capillary Action
these properties enable water to climb tree tops. Osmosis allows plants to feed and for marine creatures to absorb fresh water in increasing salt-water environments.
Most hard waters originate in areas where the top soil is ____ and limestone formations are present.
thick, limestone
When water is heated in a closed system, ____ are formed and exert _____ of the liquid. This pressure is known as vapor pressure.
vapor molecules; pressure
When water is heated in a closed system, vapor molecules are formed and exert pressure of the liquid. This pressure is known as ____.
vapor pressure
Earth
was formed as a hot molten rock, and with it the first atmosphere or primitive atmosphere.
Expansion -_____is one of the only compounds that expands when it freezes.
water
High Specific Heat Capacity - this property is of important consideration when _____is used as a medium of heat transfer.
water
contains strong covalent bonds that hold two hydrogen atoms and one oxygen atom together.
water
A considerable amount of energy is needed to raise the temperature of _____, therefore making it an effective ____
water, cooling agent.
Excellent Solvent - this property is important for many biological processes use _____ as a dispersing medium for the delivery of nutrients and waste products. It can be accounted from water's _____
water, high dielectric strength.
Ground water can be accessed in the form of ____ and _____.
wells and springs
cyanobacteria
were to the first to undergo photosynthesis
Sources of surface water pollution can be categorized as:
• Point and Non-point Sources • Natural and Anthropogenic Sources