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79 Cards in this Set
- Front
- Back
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Define atom. |
The smallest chemical unit of matter
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Define molecule.
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Two or more atoms linked together to make a substance with unique properties
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Define concentration.
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The quantity of a substance within a certain volume
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A molecule is broken down into its constituent atoms. Do these atoms have the same properties as the molecule?
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The atoms do not have the same properties as the molecule. When atoms join to make a molecule, their individual properties disappear and the molecule takes on its own, unique properties. When the molecule is broken down into its atoms, the atoms regain their individual properties.
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When salt is dissolved in water, it actually breaks down into two different substances. Is salt composed of atoms or molecules?
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Salt is composed of molecules. Since atoms are the smallest chemical units of matter in creation, if salt can be broken into smaller parts, it must be made of atoms linked together. Thus, it is made of molecules. Now you might think that since molecules are made by linking atoms together, you could also say that salt is made of atoms. However, that is not really correct. The atoms that link together to form salt molecules have their own, unique properties, but those properties completely disappear when the atoms join to form salt molecules. Thus, it is not the atoms that give the salt its properties; the molecules do.
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A student measures the mass of a book as 12,321 g. What is the book's mass in kg?
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12,321 g is the same as 12.321 kg.
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If a glass contains 0.121 L of milk, what is the volume of milk in mL?
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0.121 L is the same as 121 mL.
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In the National Basketball Association (NBA), the distance from the three-point line to the basket is 723.9 cm at the top of the arc. What is this distance in meters?
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The three-point line is 7.239 m from the basket.
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A piece of yarn is 3.00 inches long. How many centimeters long is it?
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The yarn is7.62 cm long.
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How many slugs are there in 12 kg?
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There are 0.82 slugs in 12 kg. Note that I rounded the answer. The real answer was “0.822481151,” but there are simply too many digits in that number. When you take chemistry, you will learn about significant figures, a concept that tells you where to round numbers off. For right now, don't worry about it. If you rounded at a different spot than I did, that's fine.
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If an object occupies 3.2 gallons of space, how many liters of space does it occupy?
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The object has a volume of 12 L. Once again, don't worry if you rounded your answer at a different place from where I rounded my answer.
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Muriatic acid is sold in hardware stores for use in cleaning. Pool owners, for example, use it to clean hard water stains and algae stains from their pools. Its active ingredient is hydrochloric acid. The Works ® is a toilet bowl cleaner with hydrochloric acid as its active ingredient. There are approximately 350 grams of hydrochloric acid in a liter of muriatic acid, and there are approximately 30 grams of hydrochloric acid in a liter of The Works. Why is muriatic acid a more powerful cleaner than The Works?
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Muriatic acid is the more powerful cleaner because the active ingredient is more concentrated. In the same amount of volume, muriatic acid has more than 10 times as much active ingredient. Since the active ingredient is more concentrated, it will clean better.
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Sodium is a necessary part of a healthy diet. If a person does not ingest enough sodium every day, that person will get sick and perhaps die. Nevertheless, some people try to limit their sodium intake by eating a low-salt diet. How can it be good to limit your sodium intake, even though sodium is a necessary part of body chemistry?
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Sodium is necessary for the body at a certain concentration. If you eat too much sodium, you raise the concentration too much. In the same way, if you eat too little sodium, you lower its concentration too much. Either way, your body suffers. Thus, you need to keep the sodium concentration in your body at the right level. Too little sodium intake will reduce the sodium concentration to critical levels, while too much sodium intake will raise it to toxic levels.
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If an object occupies 3.2 gallons of space, how many liters of space does it occupy?
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The object has a volume of 12 L. Once again, don't worry if you rounded your answer at a different place from where I rounded my answer.
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Muriatic acid is sold in hardware stores for use in cleaning. Pool owners, for example, use it to clean hard water stains and algae stains from their pools. Its active ingredient is hydrochloric acid. The Works ® is a toilet bowl cleaner with hydrochloric acid as its active ingredient. There are approximately 350 grams of hydrochloric acid in a liter of muriatic acid, and there are approximately 30 grams of hydrochloric acid in a liter of The Works. Why is muriatic acid a more powerful cleaner than The Works?
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Muriatic acid is the more powerful cleaner because the active ingredient is more concentrated. In the same amount of volume, muriatic acid has more than 10 times as much active ingredient. Since the active ingredient is more concentrated, it will clean better.
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Sodium is a necessary part of a healthy diet. If a person does not ingest enough sodium every day, that person will get sick and perhaps die. Nevertheless, some people try to limit their sodium intake by eating a low-salt diet. How can it be good to limit your sodium intake, even though sodium is a necessary part of body chemistry?
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Sodium is necessary for the body at a certain concentration. If you eat too much sodium, you raise the concentration too much. In the same way, if you eat too little sodium, you lower its concentration too much. Either way, your body suffers. Thus, you need to keep the sodium concentration in your body at the right level. Too little sodium intake will reduce the sodium concentration to critical levels, while too much sodium intake will raise it to toxic levels.
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Fifty grams of carbon disulfide can be broken down into 42.1 grams of sulfur and 7.9 grams of carbon. Is carbon disulfide made up of atoms or molecules?
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Molecules
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A statue is made of copper and displayed outside. After many years, what color will the statue be?
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Green
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If you put iron near a magnet, the iron will be attracted to the magnet. Rust is made up of molecules that contain iron atoms and oxygen atoms. Rust is not attracted to a magnet. If rust contains iron atoms, and iron is attracted to a magnet, why isn't rust attracted to a magnet?
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Because of the CONCENTRATION of molecules
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Have scientists actually seen atoms?
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No
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Give the numerical meaning for the prefix centi.
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0.01
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Give the numerical meaning for the prefix milli.
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0.001
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Give the numerical meaning for the prefix kilo.
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1,000
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If you wanted to measure an object's mass, what metric unit would you use?
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Gram
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If you wanted to measure an object's mass, what English unit would you use?
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Slug
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Fifty grams of carbon disulfide can be broken down into 42.1 grams of sulfur and 7.9 grams of carbon. Is carbon disulfide made up of atoms or molecules?
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Molecules
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A statue is made of copper and displayed outside. After many years, what color will the statue be?
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Green
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If you put iron near a magnet, the iron will be attracted to the magnet. Rust is made up of molecules that contain iron atoms and oxygen atoms. Rust is not attracted to a magnet. If rust contains iron atoms, and iron is attracted to a magnet, why isn't rust attracted to a magnet?
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Because of the CONCENTRATION of molecules
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Have scientists actually seen atoms?
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No
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Give the numerical meaning for the prefix centi.
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0.01
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Give the numerical meaning for the prefix milli.
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0.001
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Give the numerical meaning for the prefix kilo.
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1,000
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If you wanted to measure an object's mass, what metric unit would you use?
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Gram
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If you wanted to measure an object's mass, what English unit would you use?
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Slug
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If you wanted to measure an object's volume, what metric unit would you use?
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Liter
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If you wanted to measure an object's volume, what English unit would you use?
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Gallon
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If you wanted to measure an object's length, what metric unit would you use?
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Meter
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If you wanted to measure an object's length, what English unit would you use?
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Yard
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If a person has a mass of 75 kg, what is his or her mass in grams?
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75,000 grams
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How many centimeters are in 1.3 meters?
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130 centimeters
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How many liters of milk are in 0.500 gallons of milk?
(1 gallon = 3.78 liters) |
1.89 L
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A meterstick is 100 centimeters long. How long is it in inches?
(1 inch = 2.54 centimeters) |
39.37 inches
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Ozone is a poisonous gas that can build up in the air in dense cities. Thus, there are many environmental initiatives to lower the amount of ozone in the air. One way you can make ozone, however, is by baking bread. The nice smell that you associate with baking bread is actually due, in part, to ozone. If ozone is poisonous, why is baking bread not considered a dangerous activity?
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The concentration of the ozone gets spread throughout the surrounding air, thus it is not toxic
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Define humidity.
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The moisture content of air
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Define absolute humidity.
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The mass of water vapor contained in a certain volume of air
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Define relative humidity.
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The ratio of the mass of water vapor in the air at a given temperature to the maximum mass of water vapor the air could hold at that temperature, expressed as a percentage
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Define greenhouse effect.
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The process by which certain gases (principally water vapor, carbon dioxide, and methane) trap heat that radiates from earth
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Define parts per million.
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The number of molecules (or atoms) of a substance in a mixture for every 1 million molecules (or atoms) in that mixture
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Suppose you left a glass of water outside on two different days. On the first day, it is warm and humid. On the second day, it is the same temperature, but the humidity is low. Each day, you measure how long it takes the water to completely evaporate from the glass. On which day will the time it takes the water to evaporate be the smallest?
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The water will take the least time to evaporate on the second day. Remember, when humidity is high, there is already a lot of water vapor in the air. Thus, water does not evaporate very quickly. On low humidity days, however, there is little water vapor in the air, so water evaporates quickly.
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Suppose you did the same experiment that was described in Problem 2.1 when the relative humidity was 100%. How quickly would the water evaporate from the glass?
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You will not see any evaporation from the glass of water. When the relative humidity is 100%, no more water can go into the air, so no net evaporation can occur! Now it turns out that water will evaporate from the glass, but water will also condense back into the glass from the air. The rate at which the water evaporates will equal the rate at which it condenses, however, so no net evaporation will occur.
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If a scientist were to measure the percentages of nitrogen and oxygen in a sample of air that was not dry, would they be greater than, less than, or essentially the same as the percentages shown in Figure 2.1?
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The percentages of nitrogen and oxygen would be less. Think about this one. If there is water in the air, then the total amount of molecules in the air is greater. Well, the percentage of a substance is equal to the amount of that substance divided by the total amount in the mixture times 100. If you just add water vapor to the mixture of gases, you have not increased the amount of nitrogen, for example. Thus, the amount of nitrogen stays the same. The total amount of molecules in the mixture, however increases, because you added water molecules. As a result, when you calculate the percentage, you take the same number for the amount of nitrogen, but you divide by a larger number (for the amount of molecules in the mixture). As a result, the percentage of nitrogen goes down.
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At high altitudes, there is less air around you as compared to lower altitudes. Would a candle at high altitudes burn dimmer, brighter, or essentially the same as the same candle at low altitudes?
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The candle would burn dimmer. If there is less air around you, there is also less oxygen around you. With less oxygen, the fire will burn more slowly, making the candle dimmer.
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We know that if the carbon dioxide concentration were too low, plants would starve. Conversely, experiments indicate that many plants actually flourish when the concentration of carbon dioxide in their vicinity increases. How can this fact help explain why some experiments indicate that houseplants tend to grow better when their caretakers talk to them?
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Plants may grow better when their caretakers talk to them because when someone talks to a plant, he exhales some carbon dioxide on it. This increases the concentration of carbon dioxide in the plant's vicinity, which might make some plants grow better.
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We know that our bodies do not use the nitrogen we inhale. Nevertheless, in Figure 2.5, notice that the percentage of nitrogen in exhaled air is lower than the percentage of nitrogen in inhaled air. If our bodies do not use nitrogen in any way, why does the percentage decrease?
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You use the same reasoning here that you used in question 2.3. Since exhaled air has more molecules in it (water vapor and carbon dioxide, for example), the percentage of nitrogen decreases not because the amount of nitrogen decreases, but because the total amount in the mixture increases. Once again, the amount of nitrogen is the same in both inhaled and exhaled air. However, since there are more molecules in exhaled air, when you calculate the percentage of nitrogen in exhaled air, you take the same number and divide it by a larger number. This makes a smaller percentage.
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One popular thing to do in American politics is to note that many of the past few years have been some of the warmest ever recorded. This is then used to support the idea that global warming is happening. What is wrong with this kind of argument?
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There are at least two problems with this argument. Don't worry if you didn't get both of them. First, studies indicate that average global temperatures in the Middle Ages were warmer than they are now. Thus, even though the recorded temperatures are greater now than they have been before, we know it is not warmer now than in earth's past. If the warmer temperatures of the Middle Ages were not due to global warming, how can the current warm period that is actually cooler than the Middle Ages be a result of global warming? The second problem is even more important. Global warming is a long-term effect, and you must therefore use long-term trends in the data to support it. Notice from the lower portion of Figure 2.6 that in the late 1930s and the early 1950s, the temperatures were the warmest ever on record up to that point. However, the next 30 years experienced a long-term cooling trend. As a result, the “hot” years were offset by a number of “cool” years, so there was no long-term temperature change. As a result, the fact that we are experiencing a few years of extra warmth (notice the data from the late 1990s on) means nothing when it comes to global warming. If history is any indication, the earth will experience a cooling trend that will offset these slightly warmer temperatures.
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The concentration of argon in the air is about 0.9%. What is this in ppm?
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The concentration of argon in the air is 9,000 ppm.
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Convert 11 ppm into percent.
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A concentration of 11 ppm is equal to 0.0011%.
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One evolutionary theory of how life originated on the planet requires that, at one point, there was no oxygen in the atmosphere. This theory, of course, assumes that the first life form did not breathe oxygen. Since there are organisms today that can exist without breathing oxygen, this is not as fantastic as it may first sound. Based on what you learned in this section, however, what serious objection can you raise against the theory that life originated on an earth with no oxygen in its air?
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No oxygen means no ozone. With no ozone layer, no life form would be able to exist on the surface of the earth. Remember, the earth replenishes its ozone supply from its oxygen supply. With no oxygen, there will be no ozone.
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Suppose you could institute regulations that would be targeted at one specific air pollutant. Based on the data in Figure 2.9, which air pollutant would be best to target from a cost/benefit point of view?
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Nitrogen oxides would be the best pollutant to target, because the concentration of nitrogen oxides is still rather high. Thus, we could probably derive a lot of benefit from reducing nitrogen oxides. It turns out this is rather hard to do, however, because nitrogen oxides are produced whenever there is a lot of heat and air, and most industries, automobiles, etc., need a lot of heat.
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The temperature is the same at 1:00 PM on two consecutive days. For a person who is outside working, however, the second day feels cooler than the first day. On which day was the relative humidity higher?
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The first
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A child decides to keep his goldfish outside in a small bowl. He has to add water every day to keep the bowl full.
On two consecutive days, the temperatures are very similar, but on the first day, the relative humidity is 90% while on the second day it is 60%. On which day will the child add more water to the goldfish bowl? |
The second
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If you put a glass of water outside when the relative humidity is 100%, how quickly will the water evaporate?
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The water will not evaporate
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Why does sweating cool people down?
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When the sweat eveporates, it takes with it some of the energy on the surface of the skin
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What is the percentage of nitrogen in dry air?
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78%
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What is the percentage of oxygen in dry air?
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21%
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What would be the consequence of removing all the carbon dioxide in earth's air supply?
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If the air had no carbon dioxide in it, the earth would be colder.
OR: The plants would die of starvation |
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What would be the consequence of removing all the ozone in earth's air supply?
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If there were no ozone in the air, ultraviolet light would kill a lot of living things
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What would be the consequence of a sudden increase in the concentration of oxygen in the earth's air supply?
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If more oxygen were in the air, living things would not be as healthy and forest fires would increase in frequency and ferocity
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Suppose astronomers found another solar system in which there was a sun just like our sun. Suppose further that a planet in this new solar system was just as far from its sun as is earth from our sun. Since the vast majority of energy that planets get comes from their suns, is it reasonable to assume that the new planet would have roughly the same average temperature as that of earth? Why or why not?
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There is no reason to expect that the new planet will have the same temperature as earth. If it does not have essentially the same air, with all the same levels of all the greenhouse gases, it will not have the same temperature! Mercury, for example, is much closer to the sun than Venus. Venus, however, is warmer than Mercury, because the greenhouse effect on Venus is very strong.
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What makes up the majority of the air we exhale?
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Nitrogen makes up the majority of the air we exhale.
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Do we exhale more carbon dioxide or more oxygen?
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We exhale more oxygen.
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Do the data indicate any significant global warming?
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No
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The current concentration of ground-level ozone is about 0.110 ppm. What is that in percent?
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0.0000110%
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Suppose you had a sample of air in which the concentration of nitrogen oxides is 0.023%. What would be the concentration of nitrogen oxides be if you expressed it in ppm?
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230 ppm
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Is the air cleaner today, or wsa it cleaner 30 years ago?
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The air is much cleaner today than 30 years ago
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What is a cost/benefit analysis?
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A cost/benefit analysis attempts to determine whenther or not to take an action by determining the benefits of that action as well as the costs. If the benefit outweighs the cost, the action should be taken. If not, the action should not be taken.
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What does a catalytic converter do in a car?
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A catalytic converter converts carbon monoxide in the car's exhaust to carbon dioxide.
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What does a scrubber do in a smokestack?
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A scrubber traps sulfur oxides in a smokestack and keeps them from being emitted into the air.
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In the United States, many regulations are aimes at decreasing the amount of ground-level ozone in the air, because ground-level ozone is considered a pollutant. At the same time, many regulations are aimed at increasing the amount of ozone in the ozone layer. Despite the fact that ozone in the ozone layer is the same as ground-level ozone, ozone in the ozone layer is not considered a pollutant. Instead, it is considered an essential substance. Why?
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Ground-level ozone is a pollutant because it is a poison, and it is where we can breathe it. Ozone in the ozone layer is not a pollutant becasue no one breathes that high up in the air, so its poisonous properties are unimportant. It is necessary in the ozone layer in order to block the sun's ultraviolet rays.
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