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Key Concept Review 1. Define the term “organic compound. ” Give two examples. Complex molecules that contain carbon. Sugar Protein Fat 2. List four elements that are macronutrients for plants. Explain their importance in plants and in humans. Plants obtain the nutrients carbon, hydrogen, and oxygen from air and water. They obtain nitrogen, phosphorus, potassium, magnesium, calcium, and sulfur from the soil.
3. What is a micronutrient? Give one example. Elements that are needed in only minor or trace amounts. Example - vitamins and minerals – elements like iron Fe 4. What elements are found in the following compounds? a)carbohydrates are organic molecules made up of atoms of carbon, hydrogen, and oxygen b) Proteins an organic compound made up of units called amino acids. C, H, O, N c) Lipids compounds composed of many carbon, hydrogen, and oxygen atoms- Fats, oils, and waxes d) nucleic acids DNA and RNA made up of three substances: phosphates, a simple sugar called ribose, and nitrogen-containing molecules.
Connect Your Understanding 5. Imagine that your favourite house plant is growing well but it is not flowering. A friend suggests that your plant may be lacking phosphorus. Is that a possibility? Explain your answer. Yes – Phosphorous is a macronutrient that stimulates flower growth. 6. Explain the term “optimum amount” using one of the following as an example: potassium for plants or selenium for animals. Optimum amount is the amount that provides an organism with the best health. Too little or too much potassium for plants or selenium for animals will create problems.
7. Which term in each of the following groups of four terms includes the other three? a) carbohydrate, glycogen, starch, glucose carbohydrate b) sugar, DNA, phosphate, nitrogen containing base DNA c) fats, waxes, oils, lipids
Extend Your Understanding 8. Suppose you are a farmer and your crop is not growing as well as it has in the past. You notice that the lower leaves of the plants are turning yellow. Recall that chlorophyll gives leaves their green colour and is important in photosynthesis. Use the table on page 197 to help you answer the following questions. a) What nutrient deficiencies might be causing this problem? Nitrogen, Potassium, or Magnesium b) What would be your next step to solve the problem? Test the soil to see what nutrients are present
Check and reflect p. 209 1 -7 1 ) Define the following terms: a) Diffusion is the movement of substances from an area of higher concentration to an area of lower concentration. b) Osmosis is the movement of water across a semi permeable membrane from an area where there are more water molecules to one where there are fewer water molecules. c) Active transport is the transport of materials across a cell membrane (semi-permeable membrane) from an area of low concentration to an area of higher concentration. This process requires energy.
2. What is the substrate for the lichen in Figure 1. 30(b)? Substrate for the lichen in Figure 1. 30 (b) is rock. 3. What happens to food when you ingest it? When a human ingests food, the food is digested or broken down into smaller particles that can be absorbed into the blood stream. This process begins in the mouth and continues in the stomach and small intestine. 4. What effect do hydrolysis enzymes have on the rate at which large organic molecules break down? Hydrolysis enzymes speed up the rate at which large organic molecules break down.
5. Plants take in water from the soil. Why does the water move from the soil into a plant’s roots? Plants take in water from the soil by osmosis. Water moves from the soil where there are more water molecules into the plant’s roots where there are fewer water molecules. 6. a) How is the process of diffusion similar to active transport? Both active transport and diffusion are processes by which materials can enter plants’ roots. b) How are the two processes different? Diffusion is passive so no energy is required; active transport requires that the plant (cells) expends energy to move nutrients.
7. Why are the algae that live on snow able to survive high in the Rockies in early summer? Red snow algae photosynthesize. They have lots of sun light in the summer, as well as water from the melting snow for photosynthesis.
Assess Your Learning Key Concept Review 3. Identify two elements that are known to enhance plant growth but that limit growth if too little or too much is available. Examples in the text are potassium and selenium. Most other nutrients could be correct as well. 4. What is a sanitary landfill site? It is a place where we recycle wastes when possible and bury the rest. Also uses a plastic lining.
Connect Your Understanding 5. Use an example to help explain what a neutralization reaction is. It is when an acid and a base combine – Tums for heartburn 6. Explain the difference between organic and inorganic compounds. Give one example of each. Organic compounds are complex compounds containing carbon Organic compound – sugar Inorganic - Iron 7. Match the organic molecules with the elements that compose them. carbohydrates C, H, N, O proteins C, H, O nucleic acids C, H, O, N, P Carbohydrates - C, H, O Proteins - C, H, N, O nucleic acids - C, H, O, N, P
8. a) What do the numbers 10 -0 -0 on a fertilizer label mean? 10 % Nitrogen - 0% Phosphorous - 0% Potassium b) What type of growth does this fertilizer promote? Stimulates the production of Chlorophyll 9. a) Why do farmers use pesticides? To kill pests that attack their crops. b) Why do some people want farmers to use lower amounts of pesticides? Other insects are killed as well as the targeted pests.
10. An example may be that vehicles we drive emit substances such as nitrogen oxides that combine with water in the atmosphere and contribute to acidic deposition. Acidic deposition, in high amounts, can change the p. H of soil and water systems and affect plants, animals, and inanimate objects. Science can help us understand these impacts by providing information on vehicle emissions and on the effects of these emissions on ecosystems and on the built environment. Information on vehicle emissions could include chemical content, concentrations, interaction with other substances, and range.
11. An example related to vehicle emissions is that science can identify the type of emission and the amounts of the pollutants. Technology can design and produce tools and processes that reduce the harmful emissions. The catalytic converter is an example of a technological solution. Electric vehicles are another.
Unit C Environmental Chemistry
When you have completed this section, you will be able to: • describe and illustrate the use of biological monitoring as a method of determining environmental quality • identify chemical factors in the environment that might affect the health and distribution of living things • apply and interpret measures of chemical concentration in parts per million, billion, or trillion
2. 1 Monitoring Water Quality Clarity is not a good indicator of water quality. Clear water can sometimes be harmful to humans and other organisms Water quality is determined according to what the water is used for. Provincial and federal governments set guidelines for water quality in five categories of water use: • • • human drinking water recreation such as swimming livestock drinking water Irrigation protection of aquatic life
Biological Indicators Scientists use organisms that live in water to help determine water quality. These indicator organisms include : fish plants worms insects plankton (microscopic algae and tiny animals) protozoa bacteria viruses.
Biological Indicators a) Microbiological Indicators Microscopic organisms (bacteria) can cause serious health problems if they are present in sufficient numbers. Samples are taken to identify their presence to avoid contamination of the water supply. if the count of these organisms is too high more treatment may be necessary. Examples include : Escherichia coli (sign of sewage contamination in water)
b) Aquatic Invertebrate Species of aquatic organisms (invertebrates – animals without a backbone) may indicate unsafe water. different invertebrates prefer different living conditions
For example, the organisms living in a stagnant pond are different from those living in a pond with a higher concentration of dissolved oxygen. Water temperature and p. H can also affect the types of organisms found in an area
AQUATIC ENVIRONMENTS The place where aquatic organisms live can vary, depending on the p. H level and the amount of dissolved oxygen present. The diversity of all organisms decreases as acidity increases and as result dissolved oxygen decreases. • there will likely be no fish in water that has a p. H below 5. 0 • worms and midge larva thrive in polluted water they require only small amounts of dissolved oxygen for survival
CHEMICAL FACTORS THAT AFFECT ORGANISMS water in the environment is never completely pure. The following are most commonly monitored as indicators of water quality: • • • dissolved oxygen plant nutrients such as nitrogen and phosphorus acidity Pesticides heavy metals salts such as sodium chloride and magnesium sulfate
A pond that supports a wide variety of organisms probably has good water quality for allowing organisms to survive. However, it cannot be considered safe for humans to drink until it is tested to make sure.
MEASURING CHEMICALS IN THE ENVIRONMENT The concentration of chemicals in the environment is usually measured in a) parts per million (ppm) One part per million means that one unit of an element or chemical can be found in one million units of solution.
b) milligrams per kilogram (mg/Kg). Since this is milligrams/kilograms the units we are measuring in is also ppm In this formula I do not multiply by the 106 because by taking mg/kg that is the factor of 106 If you have this milligrams (mg) million times smaller than a kg
Calculating Parts Per Million The important thing when doing it this way here is to make sure the units are the same
Ex. 1 Suppose you make a food colouring solution by putting 99 m. L of water in a beaker and adding 1 m. L of food colouring. The concentration of food colouring in this beaker is 1 part food colouring per 100 parts solution. Calculate this concentration in parts per million. 1 ml of water = 1 g of water 1 g of food coloring x 106 = 10 000 ppm 100 g of solution
A saturated solution of Pb. CO 3 contains 0. 00011 g Pb. CO 3 in 100 g of water. What is this concentration in parts per million? . 00011 g x 106 = 1. 1 ppm Pb. CO 3 100 g water
3) What is the concentration in ppm of selenium if 1. 3 grams is found in 2, 500 kg of soil? What’s the first thing we have to do here ? convert to the same units 2500 kg of soil 2 500 000 g of soil 1. 3 g of selenium x 106 = . 52 ppm 2 500 000 g of soil
Or we could have used the second formula we discussed at the beginning milligrams per kilogram (mg/Kg). We know that 1 gram = 1000 milligrams 4) What is the concentration in ppm of selenium if 1. 3 grams is found in 2, 500 kg of soil? What’s the first thing we have to do here ? convert to the proper units 1. 3 grams = 1300 milligrams 2500 kg = 2500 kg 1300 mg of selenium = . 52 ppm 2500 kg of soil
Calculate the concentration in ppm if 8 grams of Ca. Cl 2 is dissolved in 250 ml of water. 1 ml of water = 1 g of water 8 g of Ca. Cl 2 x 10 6 = 32 000 ppm 250 g of water Method #2 mg/kg 1 ml of water = 1 g of water = 1000 milligrams 8000 milligrams of Ca. Cl 2 250 g of water =. 250 kg of water Therefore 8000 mg /. 250 kg = 32 000 ppm
Most community water supplies have 0. 5 ppm of chlorine added for purification. What mass of chlorine must be added to 100. 0 L of water to achieve this level? g of solute x 106 = ppm g of solution g of solute x 106 = . 5 ppm g of solution g of solute x 106 = . 5 ppm divide both sides by 106 100 000 g of water g of solute = . 0000005 now I can solve for g of solute 100 000 g of water g of solute =. 0000005 x 100 000 g =. 05 grams of solute (chlorine)
DISSOLVED OXYGEN Dissolved oxygen is essential for the health of aquatic life such as fish, insects, and micro-organisms. The level of dissolved oxygen in water depends on: temperature • turbulence due to wind or the speed of moving water • the amount of photosynthesis by plants and algae in the water • the number of organisms using up the oxygen •
Examples of levels of dissolved oxygen needed by aquatic invertebrates. Dissolved oxygen (ppm or mg/L) Invertebrates 8 Large numbers of diverse invertebrates 6 Mayflies, stoneflies, and beetles begin to disappear 4 Freshwater shrimp, midge larvae, and worms can survive 2 Midge larvae and some worms can survive
PHOSPHORUS AND NITROGEN CONTENT Most aquatic organisms are sensitive to changes in the amount of dissolved oxygen in the water in which they live One factor that can affect dissolved oxygen is an increase in phosphorus and nitrogen in the water. Phosphates and Nitrates often enter the water supply by sewage and runoff
Higher concentrations of these nutrients growth of algae and green plants Leads to more algae and plants grow, more die dead organic matter becomes food for bacteria that decompose it leads to more food available, the bacteria increase in number and use up the dissolved oxygen in the water leads to When the dissolved oxygen content decreases, many fish and aquatic insects cannot survive
ACIDITY normal rain and snow have a p. H of 5. 6 because carbon dioxide from the air dissolved in them to form weak carbonic acid. As the acidity increases, the diversity of plants and animals that live in this water decreases. When acidic deposits build up in ice and snow in the winter and the ice and snow melt, the acid melt water flows into aquatic systems spring acid shock (d) Periods of extreme acidity when the acid snow (ice) melts and the acidic water enters the waterways
PESTICIDES pesticides can remain in the environment after they are no longer needed. When these chemicals remain in the environment toxin is created very poisonous toxicity describes how poisonous a substance is.
scientists use a measurement called LD 50. "LD" stands for "lethal dose" and the "50" represents 50%. LD 50 is the amount of a substance that causes 50% of a group of test animals to die if they are given a specified dose of the substance all at once. Substance LD 50 Subject / How delivered Table salt 3000 mg/kg Rat, by mouth Caffeine 192 mg/kg Rat, by mouth DDT (pesticide) 87 mg/kg Rat, by mouth
HEAVY METALS In the 1950 s, many people in Minimata, Japan, were becoming sick and dying from a mysterious disease that affected their nervous systems. Investigators found that the disease could be linked to eating local fish that contained large quantities of mercury.
The mercury was traced to a chemical company that had been dumping its waste into the ocean. People who caught and ate the fish from this area were affected by mercury poisoning. The symptoms of mercury poisoning include numbness of arms and legs, involuntary movements, nerve damage, and brain damage.
Mercury belongs to a group of substances called heavy metals.
Heavy metals are elements that have a density of 5 g/ cm 3 Heavy metals can enter the environment by: • acidic water dissolving lead in pipes. • Cadmium is present in some fertilizers as an impurity
Key Concept Review 2. 1 1. Governments set water quality guidelines for five categories of water use. What are these? • human drinking water • recreation such as swimming • livestock drinking water • irrigation • protection of aquatic life
2. List four different groups of invertebrates that can be found in freshwater systems. These include insects, crustaceans (such as shrimp), worms, and mollusks (such as clams). 3. Identify five chemicals that are regularly monitored in aquatic systems. • dissolved oxygen • plant nutrients such as nitrogen and phosphorus • acidity • pesticides • heavy metals • salts such as sodium chloride and magnesium sulfate
4. What effect does spring acid shock have on aquatic organisms? It can seriously affect the eggs of aquatic organisms, as well as the young offspring of spring-spawning fish. 5. Identify an invertebrate family that would probably be among the first to die if the p. H of its habitat decreased. Mayflies
Connect Your Understanding 6. A student put 0. 03 m. L of food colouring into water to make 1000 m. L of solution. Calculate the concentration of food colouring in parts per million. 0. 03 m. L per 1000 m. L. Multiply by 1000000 to get ppm = Calculate 7. 30 ppm the concentration in ppm of an alcohol/water solution if 30 drops of alcohol are stirred into water to make 1 L of solution. Note: 1 drop = 0. 05 m. L 30 x 0. 05 m. L = 1. 5 m. L per 1000 m. L Multiply by 1000 to get ppm = 1, 500 ppm
8. Calculate the concentration of each solution in parts per million and fill in the last column. Solute (m. L) 2. 0 0. 0009 0. 62 Volume of final solution (m. L) Concentration (ppm) 1000 2. 0 m. L per 1000 m. L Multiply by 1000000 to get ppm = 2, 000 ppm 100 0. 0009 m. L per 100 m. L Multiply by 1, 000 to get ppm = 9 ppm 10 000 0. 62 m. L per 10, 000 m. L Multiply by 1000000 to get ppm = 62 ppm
9. Look at the table below. In which location (A or B) will the water support the greatest diversity of organisms? Characteristic Sample A Sample B Dissolved oxygen 3. 5 6. 0 p. H 5. 5 6. 5 Phosphorus high low Location with Sample B – more O 2 p. H closer to 7 – Low Phosphates
10. Explain the following statement about table salt: The LD 50 is 3000 mg/kg for rats. When rats ingest 3000 mg/kg of salt 50% of the rats will die Extend Your Understanding 11. Explain what happens when a high concentration of phosphorus enters a water system. Some plants die. Bacteria help to decompose them. With more food available, the population of bacteria increases. They need oxygen to survive, so they use up much of the dissolved oxygen in the water. The lake is no longer a place where fish and many insects can live.
2. 2– Monitoring Air Quality
Composition of Air Nitrogen (78%) Oxygen (21%) Carbon Dioxide (0. 03%) Hydrogen & Neon (tiny amounts only) (Argon (<1%)
Air quality can be measured in two ways: 1)by measuring the levels of pollutants in the air 2) by estimating the amount of emissions from pollution sources.
Pollutants In the air 1) Sulfur Dioxide ( SO 2(g) ) is a major air pollutant (forming smog and acid rain). Effects respiratory system and irritate your eyes Industrial processes produce SO 2
Scrubbers are used to reduce sulfur dioxide emissions by up to 99%
They use limestone to convert it to a useful product gypsum can be recovered and turned into gypsum board
2) Nitrogen Oxides ( NO x(g) ) are mixtures of NO and NO 2 Major contributor to smog and acid rain Contributors Vehicle Emissions & Burning fossil fuels
3) Carbon Monoxide called the silent killer because it is a colorless, odorless gas
caused by the burning of fossil fuels and not enough oxygen to produce carbon dioxide. Catalytic converters are used to convert carbon monoxide into carbon dioxide.
If inhaled CO can ü reduces the amount of oxygen in the blood ü cause headaches, ü sleepiness, ü chest pains, ü brain damage ü death.
Ground-Level Ozone O 3 (g ) is an odorless, colorless gas that has 3 oxygen atoms. Ground-level ozone forms from reactions between oxygen, nitrogen oxides and compounds that are volatile organic compounds (VOC’s), in the presence of sunlight and heat.
Ozone high in the atmosphere usually protects us from harmful ultraviolet rays from space, at ground-level it can be harmful, because it can affect the respiratory system, deteriorate plastics and can have serious effects on crops.
Ozone is especially harmful to: 1. people who have asthma or colds. 2. All children are at a higher risk because their lungs are still developing. 3. Anyone who exercises outside in air containing high levels of ozone may suffer breathing problems and longterm lung damage. Check and reflect : p 228 1 -8
Key Concept Review 1. Match the chemicals that are components of air in column A with their correct percent composition in column B. Column A Column B oxygen 21% 78% carbon dioxide 0. 03% 21% 78% nitrogen less than 1% argon 0. 03% less than 1% hydrogen trace 2. Scrubbers use a chemical reaction to remove a major pollutant from the air. a) What pollutant is removed? sulfur dioxide b) What are the products of the chemical reaction? gypsum
3. Why is carbon monoxide harmful to animals? carbon monoxide reduces the amount of oxygen in the blood and can cause headaches, sleepiness, chest pains, brain damage and death 4. Scientists have two main methods of determining the amount of pollution in the air. Explain why a) is a more accurate method than b). a) measuring the concentration of harmful chemicals in the air b) estimating the amount of harmful chemicals in emissions a more accurate because other sources Measuring is from industrial plants and you actually monitor the chemicals that are in the air Connect Your Understanding 5. Ozone can be both helpful and harmful. Explain this statement. The Ozone layer protects us from harmful UV rays. At ground level it can affect the respiratory system, deteriorate plastics and can have serious effects on crops.
6. Look at the graph in Figure 2. 14. What trends do you see in the following sectors? a) total amount (top line) c) oil sands b) natural gas processing d) electric power generation Figure 2. 14 Alberta sulfur dioxide emissions by sector for questions 6 and 7 (Graph supplied by Alberta Environment) a) The total amount will be reduced by almost Kilotonnes b) The total amount will be reduced by almost 200 Kilotonnes c) The total amount will increase by about 18 200 Kilotonnes d) increase by about 100 Kilotonnes
7. Which process has contributed to a reduction in total sulfur dioxide emissions in Alberta since the early 1970 s? Suggest a reason for this. Natural Gas – Better technology Extend Your Understanding 8. a) Identify the harmful compounds in car exhausts and explain why they are harmful to the environment. Nitrogen Oxides and Carbon Monoxide – Acid Rain b) Explain one benefit of catalytic converters. Reduce the amount of Nitrogen Oxides and Carbon Monoxide c) Explain why catalytic converters have become an issue for people concerned about global warming. Produce Carbon Dioxide – greenhouse gas
2. 3 Monitoring The Atmosphere chemicals in the atmosphere can have serious global effects. Ozone depletion and climate change are the primary concerns internationally.
Carbon Dioxide As A Greenhouse Gas Carbon dioxide occurs naturally in the environment, but increasing amounts of are being produced by various human activities creating a concern globally through increasing use of fossil fuels is creating some issues.
The Greenhouse Effect ü naturally occurring event ü greenhouse gases (water vapor, CO 2, + other gases) traps some outgoing energy retaining heat similar to the glass panels of a greenhouse. ü helps to maintain the Earth's average surface temperature of 15°C.
Suns rays shine down on the Earth and while some energy is absorbed by the ground, most of heat is radiated back into the atmosphere. The greenhouse gasses which form naturally in the atmosphere reflect some of the heat back, making the Earth warm enough for plants and animals to live.
The Enhanced Greenhouse Effect Many scientists support theory that the enhanced greenhouse effect is causing temperatures to increase around the world. burning of fossils fuels is the primary reason. Global Warming. It is not just human activities that are contributing to global warming volcanoes and forest fires are also part of the cause.
1) What is being indicated by this graph? 2) Why are these locations being chosen for recording the data being presented
The Ozone Layer we already know that ground-level ozone can have dangerous effects. The ozone layer is a natural formation of ozone 15 to 50 km above Earth’s surface chemical that maintains a shield around the Earth protecting everyone from harmful UV radiation from the Sun.
Scientists have been monitoring the ozone layer since the late 1970 s. Over the years, they have noticed that this layer has become thinner, allowing more UV radiation to reach Earth’s surface. Some areas are so thin that they are called "holes" in the ozone.
This loss of ozone results in greater exposure to UV radiation on Earth’s surface Lead to increased human skin cancer and cataracts. Plankton are sensitive to UV exposure, so increased UV radiation could cause plankton to die. This would affect all the animals that feed on plankton.
The Role of Chlorofluorocarbons the thinning of the ozone layer is caused by our use of chemicals called chlorofluorocarbons (CFCs). CFCs have been used in many different applications, including refrigerators, aerosol cans for products such as hair spray, and fire extinguishers.
In the upper atmosphere, UV radiation breaks them down into substances, such as chlorine, that destroy ozone One chlorine atom can remove 100 000 ozone molecules Check and reflect 1 -9 Section review 1 -11
Key Concept Review 1. List four greenhouse gases. By effect, the most important greenhouse gases are: water vapor, which causes about 36– 70% of the greenhouse effect on Earth (Note clouds typically affect climate differently from other forms of atmospheric water. ) carbon dioxide, which causes 9– 26% methane, which causes 4– 9% ozone, which causes 3– 7% Other greenhouse gases include, but are not limited to, nitrous oxide and chlorofluorocarbons
2. International panels have been set up to study global warming and climate change. Describe three outcomes of global warming that are of concern. Produce changes in precipitation patterns, storm severity, and sea level.
3. a) What factor has contributed to the thinning of the ozone layer? The thinning of the atmosphere is caused by our use of chlorofluorocarbons ( CFC’s ). b) What is happening as a result of this thinning? This results in more UV radiation getting through to the surface of the Earth and increasing the likelihood of more organisms getting skin cancer and cataracts. 4. What are countries doing to protect the ozone layer? Many countries have signed agreements to reduce their use of these chemicals.
Connect Your Understanding 5. What trend has been observed in carbon dioxide levels over the past century? They have been increasing at an alarming rate Describe two suggested causes of this trend. Burning of Fossil fuels and increase in Human population
6. Explain the difference between the greenhouse effect and the enhanced greenhouse effect. The enhanced greenhouse effect traps more energy. 7. In which months would you expect the carbon dioxide levels to be lowest in Alberta? Explain why you chose those months. Summer – less fossil fuels are burned and there is more plant activity.
8. Match the four statements below with the following fields of study: political, scientific, economic, or technological. Suggest one question for further study that could be asked in each case a) Carbon dioxide levels have been measured analyzed. They have been rising since the Industrial Revolution. scientific b) Scrubbers use calcium carbonate (limestone) to remove sulfur dioxide from smokestack emissions. Technological c) Governments limit and monitor emissions such as sulfur dioxide and nitrogen oxides. political d) People are demanding inexpensive electricity. Removing pollutants from smokestacks is expensive. Who will pay for it? economic
Extend Your Understanding 9. At Biosphere 2 near Tucson, Arizona, scientists are studying the growth of poplar trees in three different concentrations of carbon dioxide. Evidence suggests that slight increases in carbon dioxide levels stimulate plant growth. Why do you think this occurs? Plants use carbon dioxide to make sugar Figure 2. 20 Biosphere 2 is a closed ecosystem laboratory used to investigate ecosystem interactions. It contains five biomes—a rain forest, a desert, a savannah, a marsh, and an ocean. It is about 30 m tall at its highest point.
Assess Your Learning Key Concept Review 1. What do the presence of fish and a wide diversity of invertebrates in a river indicate? Quality of the water 2. Why is it important to have long-term measurements when studying ecosystems? To see if conditions are changing 3. a) List six heavy metals that can be taken up by plants. mercury, copper, lead, zinc, cadmium and nickel. b) Why are they considered pollutants? Heavy metals can be toxic to a wide range of organisms,
4. Identify the organisms in Figure 2. 21. Clam Stonefly Nymph Mayfly Nymph Flatworm
Characteristic Sample A Sample B p. H 6. 5 5. 5 Dissolved oxygen 5. 5 4. 5 Phosphorus low high Nitrogen low high Mayflies present absent 5. The table above shows monitoring data from two water systems. Which statement below is correct? a) Sample A indicates good water quality for aquatic life because there are low concentrations of phosphorus and nitrogen. b) Sample A indicates poor water quality for aquatic life because there are many mayflies. c) Sample B indicates good water quality because there are high concentrations of phosphorus and nitrogen. d) Sample B indicates good water quality because the p. H is basic and mayflies are absent. 5 A
6. You have an air sample that has 0. 02 m. L of carbon dioxide in 1000 m. L of air. What is the concentration of the carbon dioxide in parts per million? 0. 02 X 1000 =. 00002 x 1, 000 = 20 ppm 7. Describe two situations that reduce the dissolved oxygen content of water. Phosphates – causing increased plant growth which cause increased bacterial growth. Lack of water flow. Extended winter – ice coverage
8. Match the words/phrases in column A with the descriptions in column B. A B LD 50 chemical used to kill insects neutralize to bring closer to p. H 7 insecticide sudden lowering of p. H scrubber measures toxicity spring acid shock removes SO 2(g) LD 50 - measures toxicity neutralize - to bring closer to p. H 7 insecticide - chemical used to kill insects scrubber - removes SO 2(g) spring acid shock - sudden lowering of p. H
9. Explain how the enhanced greenhouse effect may cause global warming. Enhanced greenhouse effect means that there is more energy from the sun being trapped by greenhouse gases causing global warming Extend Your Understanding 10. Explain how the invention of the motor vehicle has been both beneficial and harmful. It has allowed people to move goods and services all over the world but it has also increased pollution 11. How does reforestation affect the concentration of carbon dioxide in the air? Trees use carbon dioxide from the atmosphere