Name:



Name: ____________________________

Nature of Science TAKS Review

Percentages

You will be expected to know how to calculate percentages.

What is a percentage?

The percent sign ( % ) is just the short way of writing “divided by 100”

Graphs

Understanding how to read graphs is a very important skill that is always tested.

|Element |Percent |

|Sulfur |28.68 |

|Copper |28.42 |

|Iron |24.98 |

|Oxygen |9.54 |

|Other |8.38 |

|Total |100 |

Patterns and Trends

|Container |A |B |

|Volume of Water (mL) |25 |25 |

|Temperature (oC) |-15 |25 |

|Time Required (h) |72 |24 |

Collecting Data

Drawing Conclusions

|Lightbulb Intensity (W/m2) |Number of Bubbles |

| |per Minute |

|25 |4 |

|50 |7 |

|75 |12 |

|100 |31 |

|125 |38 |

Precision and Consistency

Lab Equipment

Here are just a few of the pieces of equipment you will need to know:

Lab Safety

Recycling and Conservation

-----------------------

32

100

0.32 = = 32%

%

hundredths place

%

x 100 = %

Part

Whole

2. What is the efficiency of an air conditioner if there is a work input of 320 J and a work output of 80 J?

A 4%

B 25%

C 240%

D 400%

3. From 1942 to 1945, U.S. nickels were made of an alloy that contained 35% silver, 9.0% manganese, and the rest copper, by mass. If one of these nickels has a mass of 5.0 grams, what is the mass of the copper?

A 0.5 g

B 1.8 g

C 2.2 g

D 2.8 g

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Use the figure and your knowledge of science to answer Question 1.

1. Approximately how much of the energy available in the tissues of the producer is eventually incorporated into the tissues of the secondary consumer?

A Less than 1%

B Between 20% and 30%

C Approximately 50%

D More than 50%

4. Which of these would have the greatest percent of fat content by mass?

A A food with a net mass of 29 grams and with 10 grams of fat.

B A food with a net mass of 35 grams and with 13 grams of fat.

C A food with a net mass of 45 grams and with 15 grams of fat.

D A food with a net mass of 56 grams and with 17 grams of fat.

So how do you do it?

What is 20% of 250?

20% x 250 =__________

(20/100 x 250)

Throughout this packet, you will be utilizing 3 major types of graphs:

_________, _________, and _________ graphs.

In a Line Graph:

Slope is the __________ _____ _______________.

The __________________ the slope is, the __________________ things are changing.

(If the slope is flat, then things are ________ changing!)

Pie Graphs are great tools for _________________ data.

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4. The graph shows the distance traveled by a vehicle over a certain period of time. Which segment of the graph shows the vehicle moving with the greatest speed?

A L

B M

C N

D O

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1. The graph shows the percentage of hemoglobin that combines with carbon monoxide (CO) at various concentrations. Exposure to 400 parts per million of CO in air can cause people to experience nausea and a throbbing headache. According to this graph, about what percentage of hemoglobin is bound to CO at a CO concentration of 400 parts per million?

A 25 %

B 35 %

C 40 %

D 55%

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2. The graph shows the results of a study testing chemical pesticides on a pest species common to cotton plants. Different chemical pesticides were used in five different areas. According to these results, which of the following is the most effective chemical for controlling this pest species?

A R

B S

C T

D V

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3. The graph shows metabolic rates for two types of fish at different environmental temperatures. Which of the following conclusions can be drawn from these data?

A Fish metabolism responds to temperature changes.

B Metabolic rates decrease as environmental temperatures increase.

C Fish body temperatures results from high metabolism.

D Metabolic rates are independent of environmental temperature.

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5. The graph shows the relative basal metabolic rates of a field mouse and an anole (a type of lizard) at different temperatures. According to this information, the field mouse -

A uses the least energy when the environmental temperature is 30oC

B is able to control its body temperature

C uses less energy at 20oC than the anole does

D is unaffected by environmental temperatures

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A

B

C

D

7. While studying the relationship between the pressure and the volume of a gas, members of a science class conducted an experiment in which they changed the pressure on a balloon and then measured the balloon’s volume. They collected the data above. Which graph correctly represents the data?

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6. The graph shows the amount of carbon-14 in tissue over time. According to the graph, if a bone contains 1/8 the amount of carbon-14 that it did originally, its approximate age is -

A 5,700 years

B 11,400 years

C 17,100 years

D 22,800 years

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8. At which temperature do KBr and KNO3 have the same solubility?

A 27oC

B 48oC

C 65oC

D 80oC

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Composition of a Copper Ore

10. Which graph best shows the comparison of the elements to the total composition of the copper ore?

A

B

C

D

9. According to the graph, at what temperature will 100g of water be saturated with NaClO3 if 140 grams of NaClO3 are dissolved?

A 0oC

B 38oC

C 49oC

D 62oC

Test Taking Tip: Many questions on the TAKS test can be answered by simply observing the patterns or trends that are present in tables, graphs and diagrams. When you are presented with one of these, look to see if you can find a pattern.

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5. According to the data in the table, about how far can a spring be expected to stretch when a force of 3.92 N is applied?

A 10.5 cm

B 13.6 cm

C 14.0 cm

D 17.3 cm

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1. According to the graph, what is the approximate half-life of carbon-14?

A 5.7 years

B 5,700 years

C 23,000 years

D 1,000,000 years

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2. The table shows an amino acid comparison of cytochrome c, a protein involved in cellular respiration in aerobic organisms. The two organisms in the table that are least genetically related are the –

A silkworm moth and the fruit fly

B silkworm moth and the screwworm fly

C fruit fly and the screwworm fly

D fruit fly and the hornworm moth

3. The diagram illustrates how some characteristics of the horse have changed over time. Along with the difference in size, what is another anatomical difference between the modern horse and its ancestors?

A The structure of the tooth has been adapted for eating meat.

B The size of the molars has decreased.

C The length of the forefoot has decreased.

D The number of toes has decreased.

4. According to this information, what is the best prediction for the boiling point of the seven-carbon alcohol?

A 169oC

B 178oC

C 186oC

D 192oC

Every hypothesis and theory must be supported by ____________________.

The hypothesis states what the scientist will ________________,

and what he thinks this change will ______________ to happen.

(To determine what a scientist’s hypothesis was, just look at the things that ________________.)

A hypothesis must be valid; emotions and opinions do not make a valid hypothesis.

Emotions are NOT ______________. Opinions are NOT ______________.

4. As temperature drops to the dew point, clouds form in the atmosphere, and dew forms on the ground surfaces. A scientist proposes that adding more water molecules to the atmosphere will change the dew point. This proposal is-

A an invalid observation

B a valid hypothesis

C an invalid problem

D a valid conclusion

9. The smell of ammonia solution used to clean a floor can quickly be detected throughout a house. Scientists explain this phenomenon by theorizing that gas molecules from the ammonia are in continuous random high-speed motion, drifting rapidly and permeating the air. Which statement best demonstrates the strength of this theory?

A Scientists have observed tiny smoke particles moved by unseen particles in a rapid, irregular fashion.

B Scientists have unanimously agreed on this theory since Thomas Graham’s experiments in the 1820s.

C The possibility of another theory being formed to explain the phenomenon as well is very remote.

D Reason, as opposed to experimentation, is superior to any explanation found through chemical testing.

1. Objects of the same mass but different sizes and shapes were dropped from a given height. Their rates of free fall were measured and recorded. Which of the following is most likely the question this experiment was designed to answer?

A How does height affect the force of gravity?

B How does gravity affect objects of different densities?

C How do mass and weight affect falling objects?

D How do size and shape affect an object’s rate of free fall?

2. Which of these is a hypothesis that can be tested through experimentation?

A Bacterial growth increases exponentially as temperature increases.

B A fish’s ability to taste food is affected by the clarity of aquarium water.

C Tadpole’s fear of carnivorous insect larvae increases as the tadpoles age.

D The number of times a dog wags its tail indicates how content the dog is.

Clouds are more beautiful on winter days than on summer days

3. This statement is a poor hypothesis because it is not –

A a question

B testable

C observable

D a comparison

8. In the past, people thought that life arose spontaneously out of non-living material. This belief was based partly on the observation that vegetable broth swarmed with microorganisms after sitting out for a few hours. Louis Pasteur believed spontaneous generation was impossible. Which statement below would best support Pasteur’s belief?

A Broth that was kept clean of airborne dust particles shows no signs of life after many days.

B A review of other scientists’ work shows that those scientists made many observations.

C If distilled water is substituted for broth, no microorganisms are revealed after a few hours.

D Philosophical arguments offer no support for spontaneous generation.

Time Required for Water Evaporation

5. The table shows times required for water to evaporate from identical containers. Which of these is the best question to ask before developing a reasonable hypothesis to explain the data?

A Why does a lower temperature slow the rate of evaporation?

B What is the boiling point of the water after both samples are heated?

C Why does water exist as a solid at –15oC and as a liquid at 25oC?

D How does the rate of evaporation change when a different container is used?

A scientist has hypothesized that the existence of life on Mars is likely because Mars’s atmosphere is 95% carbon dioxide.

6. Which question is valid in testing this hypothesis?

A Do most other scientists agree with the hypothesis?

B Could abiotic processes account for the carbon dioxide?

C What is the percent of argon compared to carbon dioxide in the Martian atmosphere?

D Have scientist’s other predictions about Mars been validated?

Students placed equal amounts of bread mold on 12 identical agar plates containing the same amounts and types of nutrients. Four plates were kept at 0oC, four were kept at 45oC, and four were kept at 22oC (room temperature). The plates were examined after five days.

7. Which of the following was probably the hypothesis for this experiment?

A The growth of bread mold increases as temperature increases.

B The type of nutrients causes bread mold to grow faster at higher temperatures.

C The size of the plates determines the temperature of bread mold.

D The temperature of bread mold is determined by the mold’s growth.

10. Two science students discovered that the mass of a sample of acetone in an open beaker decreased within a few minutes. One student hypothesized that the acetone reacted with the oxygen to form a gaseous compound that escaped. The other student believed that the acetone evaporated into the air. What should the students do to test these hypotheses?

A Combine the hypotheses so they give valid predictions of the acetone’s behavior

B Conduct a study of original papers describing the experiments leading to the acetone’s discovery

C Perform an experiment that attempts to identify the gas above the open beaker

D Ask a classmate’s opinion about the chemical and physical properties of acetone

In an experiment, the scientist tries to only change the ____ thing he is studying.

(This is the independent variable.)

Everything else is kept _________________.

(Constants are things that are the same in every trial.)

A ______________ group is always used in an experiment as a comparison.

(In the control group, everything is kept as natural as possible.)

Too many variables can make an experiment ______________.

1. An herbal company advertises that its product will help people lose weight if they take a tablespoon of the product with a glass of water at bedtime each night. Weight loss is guaranteed if a person does not eat for at least 3 hours before bedtime, gets moderate exercise, and drinks 8 glasses of water each day. Why is the company’s claim difficult to verify?

A The company has yet to disclose the identity of its special herb.

B Numerous uncontrolled variables are involved in evaluating results.

C Fasting lessons the absorption rate of the herb.

D The advertisement lacks data from before and after the weight loss.

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2. The diagram shows different setups of an experiment to determine how sharks find their prey. Which experimental setup is the control?

A Q

B R

C S

D T

3. An engineer has created a new engine for race cars. It is necessary to know which fuel mixture will allow the engine to run at its peak performance. Which experimental design is best for this investigation?

A Use one fuel mixture on the engine and measure its performance

B Use one fuel mixture on many types of engines and measure their performance

C Use various fuel mixtures on the engine and measure its performance

D Use various fuel mixtures on many types of engines and measure their performance

Large sample sizes should be taken so that there will be __________________ data.

(The larger the sample size, the more accurate the data will be.)

Samples should always be taken ___________________ during an experiment.

(Random sampling also allows for more accurate data.)

Setting up the Experiment

1. In experiments, a benefit of larger sample sizes would be more -

A variables

B representative data

C time per group

D control groups

2. In an investigation 10,000 dung beetles were examined for the presence of parasites. The data showed that about 5% of the beetles had parasites. The results are –

A invalid because only dung beetles were examined

B unsupported because the parasite population was small

C erroneous because more beetles should have had parasites

D valid because the sample size was sufficient for accuracy

3. The following boxes represent a field. Which pattern for collecting 10 samples would provide the best data for identifying the types of plants in a field?

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A

B

C

D

Conclusions are ALWAYS based on ______________.

(You must always base your conclusions on facts found during the experiment.)

11. Which question cannot be answered by experimentation using a scientific approach?

A Does hot water freeze faster than cold water?

B Will wearing a copper bracelet reduce arthritis symptoms?

C Do roses smell better than carnations?

D Will popcorn kernels soaked in water produce a greater volume of popped corn than dry kernels?

2. Ten different types of culture media were inoculated with the same strain of bacteria and incubated at the same temperature. Nine of the cultures grew. Which of these conclusions can be drawn from this information?

A The media used in the experiment are all capable of sustaining bacterial growth.

B The temperature varied greatly during the experiment.

C Only the culture that failed to grow bacteria was inoculated properly.

D One of the media lacked the nutrients needed for the bacteria to grow.

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Ten frogs were placed in a large container with three sections. Each section had equal amounts of light, shelter, food and water. Each section was painted a different color: red, green, and blue. Daily observations were made of the frogs’ locations for six weeks. These data were compiled to produce the following frog location frequencies.

Red area = 31%

Green area = 35%

Blue area = 34%

3. Which conclusion about the frogs is supported by these data?

A Four frogs out of ten preferred the green area.

B The frogs randomly moved into the colored areas.

C Most frogs tended to avoid the red area.

D Most frogs preferred the color blue.

Variation in Photosynthetic

Rate of Elodea

4. The table shows the number of bubbles released by an elodea plant per minute at different light intensities. The rate of bubble release is representative of the photosynthetic rate. Which statement is supported by these data?

A The rate of photosynthesis is slowest when elodea produces 7 to 12 bubbles.

B Lower light intensity causes higher photosynthetic rate.

C The greatest difference in photosynthetic rate is between the 75 W and 100 W lightbulbs.

D Light intensity has little effect on the rate of photosynthesis of elodea

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1. Which conclusion can reasonably be made about Glycotac based on the promotional brochure?

A All people with diabetes can safely use the product.

B Glycotac is guaranteed to lower blood sugar in people without health problems.

C Using the product may lower blood-sugar levels.

D Glycotac eliminates the need to exercise to control high blood sugar

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Body Length of Mosquitoes

in a Specific Area

5. Which of these conclusions can be made based on the graphs shown above?

A Larger mosquitoes have migrated into the area.

B Smaller mosquitoes are being eaten by larger mosquitoes.

C A mosquito length 2 cm has become a disadvantage in this environment.

D Mosquitoes with a body length of 3 cm have the longest life span.

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6. An environmental-science company measured the ozone pollutant levels at two different locations in a metropolitan area. Which statement is best supported by these data?

A Lower fuel efficiency and northerly winds in the winter increase ozone pollution the most.

B Northwest winds in the spring transport ozone pollution into the metropolitan area.

C High summer temperatures and southerly winds contribute to high levels of ozone.

D Heavy use of automobiles changes ozone levels the most.

Test Taking Tip: When you are drawing a conclusion, you have to base your conclusion on the data given. This means that they have to give you the answer! Do NOT rely on anything but the data that is given to you. If an answer choice is about something not mentioned or goes against the given data, it is NOT the right answer.

The most precise and consistent,

Is the one with the smallest ___________________.

Being able to consistently reproduce an experiment is very important in science.

(This means that you keep getting the same answers.)

One of the best ways to do this is to use the most ______________ equipment.

1. Which of the following will allow measurement of a liquid’s volume with the greatest precision?

A 50 mL cylinder graduated in 1 mL increments

B 100 mL cylinder graduated in 0.5 mL increments

C 100 mL cylinder graduated in 1 mL increments

D 200 mL cylinder graduated in 5 mL increments

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2. Four lab groups measured the volume of acid required to neutralize a standard solution of sodium hydroxide base. Which of the groups measured the volume with the highest precision?

A

B

C

D

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3. The table shows four mass readings of one object as measured by four different balances. Which balance produced the most-consistent measurements?

A Q

B R

C S

D T

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Important Fact: The instrument with the smallest increment may not be the largest instrument. It does NOT matter. It is still the most precise!

A

B

C

D

4. Which of these will give the most precise measure of a 10-milliliter volume?

Volumes are measured with a _________________ ___________________

(To read a graduated cylinder, you read the ________________ of the meniscus.)

Masses are measured with ________________ or ___________________.

(You place crystals on weighing paper before you take their mass.)

Temperature is measured with a __________________________.

pH is measured with ______________ paper or a _____ ______________

Distances are measured with a __________________.

(Do NOT forget that there is one of these on your formula chart.)

Test Taking Tip: When you are trying to determine what a lab setup is being used to determine, just look at what equipment is being used and think about each item’s purpose in the lab. The answer will seem obvious if you just think about each piece of equipment.

6. Which lab setup would be appropriate to use in heating 100 mL of water to the boiling point?

A A 10 mL test tube held above a Bunsen burner

B A 200 mL beaker placed on a hot plate

C A thermal coil inside a 100 mL cylinder

D A sealed 300 mL flask in a warm-water bath.

4. Which of the following procedures should be used in finding the mass of crystals?

A Pour the excess crystals back into the original container

B Put the crystals on the outer part of the balance pan for massing

C Pour wastes down the sink with plenty of water

D Use weighing paper on the balance pan

1. Which procedure is best to use when determining the density of a rock?

A Place the rock in a water-filled beaker and find the height at which the rock floats above the water.

B Use a ruler to measure the rock’s dimensions and then find its mass using an analytical balance.

C Measure the mass of the rock on a balance and then find the volume of water it displaces in a graduated cylinder.

D Place the rock in three liquids with different known densities and observe which liquid the rock floats in.

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5. The illustration shows volume levels of a liquid in a graduated cylinder before and after a sample was removed. According to this information, what was the volume of the sample to the nearest milliliter? Record your answer in the boxes below.

.

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2. The diagram shows an experimental setup. Which of these questions was this experiment designed to answer?

A Does water boil when exposed to air?

B Will fire turn a gas into a liquid?

C Does air expand when heated?

D Will heat turn a gas into a solid?

3. Which set of equipment would be best to use to test the effect of temperature on solution acidity?

A A balance and a thermometer

B A pH meter and a barometer

C A balance and litmus paper

D A thermometer and a pH meter

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7. What is the volume reading for the solution in the pipette?

A 19.4 mL

B 19.6 mL

C 20.4 mL

D 20.6 mL

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10. This experiment probably was set up to determine –

A how much mechanical energy the battery produces

B the pH of water during electrolysis

C the pressure created by an electric current

D how much energy is converted to heat

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A

B

C

D

8. Which of the following shows the length of a rubber strip measured precisely to 1.4 centimeters?

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A

B

C

D

11. Which of the following pieces of equipment would be most appropriate for measuring the volume of a marble?

9. Which set of materials would be most appropriate to use in testing the effects of stirring on the dissolving rate of a solute?

A Flask, petri dish, metal rod, scale, magnifying glass

B Beaker, glass rod, balance, graduated cylinder, timer

C Test tube, filter paper, funnel, flask, ring stand

D Flask, Bunsen burner, ring stand, petri dish, thermometer

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While you are in the lab, you should always wear _______________ and an ______________.

When should you wear gloves in a lab?

___________________________________________________

What should you do when you see any type of dangerous situation? ________________

_____________________________________

What should a student with long hair do before a lab?

____________________________

Open-toed shoes

Loose clothing

Horseplay

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FUMES:

When working with toxic fumes, always work in a __________ __________.

When smelling fumes, always ____________ them towards your nose.

(NEVER stick your nose directly over a container of chemicals.)

Store chemicals in a clean, dry place and never put them back in their original containers to stop

_______________________.

To dilute acids, pour the _______ into the __________ while slowly stirring.

2. All of these procedures should be followed for lab safety except -

A immediately reporting all dangerous activity

B wearing gloves when necessary

C using eye protection as needed

D putting used chemicals back in the original containers

1. Laboratory equipment is cleaned and properly stored after use primarily so that –

A chemical products can be measured and recorded as data

B time is saved in setting up the next experiment

C toxic materials can be kept in the laboratory

D the possibility of contamination in the laboratory is minimized

Potential Hazards of Petroleum Naphtha, Hexane, Toluene, and Acetone

May cause eye, skin, nose, and throat irritation. Inhaling or swallowing vapors may be harmful or fatal. Known to cause birth defects. Vapor may ignite explosively.

3. The ingredients described above are used to make a bonding agent. The most important safety precaution to take when applying this bonding agent is to –

A dry it with a small flame

B work in a well-ventilated area

C cover the work area with newspaper

D wear a lab coat

6. Which safety precaution should be observed while analyzing sediment from a marine aquarium?

A Wear rubber gloves

B Use a fume hood

C Avoid using glassware

D Have a fire extinguisher nearby

An activity is designed that allows a student to observe the temperature changes in a cup of water. A piece of metal taken from a beaker of boiling water is placed in a cup containing water at room temperature. A glass alcohol thermometer is used to measure temperature changes.

4. A safety checklist for this activity should include the presence of a proper fire extinguisher and all of the following items except –

A fire blanket

B receptacle for broken glass

C laboratory apron

D squeeze bottle

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7. All of these procedures must be followed when using the setup shown above except –

A putting on safety goggles

B handling the beaker with tongs

C securing loose clothing

D wearing rubber gloves

8. Reactions that produce toxic gases should be performed in a –

A laboratory fume hood

B beaker with a watch glass top

C well-ventilated area of the lab

D warm, airtight drying oven

9. Classification symbols for certain fire extinguishers are shown below. Which class of fire extinguisher should be used when a hot plate overheats and catches on fire?

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5. The safest way to dilute concentrated sulfuric acid is to add –

A a series of small volumes of water to the acid while stirring slowly

B the acid to water slowly while stirring constantly

C the acid to a small volume of water and then add more water

D dilute sulfuric acid to a small volume of the concentrated acid

11. A science class is conducting an experiment that produces noxious fumes. Because of inadequate ventilation, some students begin to feel nauseated and dizzy. The first response should be to –

A neutralize the acid that is reacting to produce the noxious fumes

B carry the reactants outside, away from the other students

C leave the room and go to an area with fresh air

D spray the reaction with a fire extinguisher

10. The reason for wafting or fanning a small amount of chemical vapors toward the nose as a means to detect odors in a test tube is to –

A avoid experimental error from excessive loss of mass of reactants or products

B avoid splashing chemicals into the face of any person

C protect the respiratory tract against potentially harmful vapors

D determine the relative strength of the odor before smelling directly

The best tool you have for answering these questions is your

______________________

SENSE.

Reduce

Reuse

Recycle

Whenever natural resources can be recycled or conserved, it is good for the environment.

What are some things that can be recycled?

______________________________________

What are some ways that natural resources can be conserved? ___________

_________________________________________________________________

3. In West Texas and Southern California, high winds drive turbines that generate electricity. One advantage that wind energy has over energy generated from solar cells is that wind energy –

A is plentiful everywhere

B can be generated at night

C produces cleaner energy

D is free of environmental hazards

2. Which of these activities can help conserve natural resources?

A Recycling cardboard boxes

B Washing small loads of laundry

C Driving large cars

D Building wooden fences

4. Battery-powered cars produce less air pollution than gasoline-powered cars. However, one environmental concern of using battery-powered cars is that batteries –

A are heavier than gasoline engines

B waste more energy than gasoline engines

C contain toxic substances that are difficult to dispose of

D produce direct current rather than alternating current

1. All of these materials can be recycled except –

A aluminum

B lumber

C glass

D coal

Hypothesis

5. Batteries produce electricity by means of a chemical reaction. Some batteries are disposable. The reactants of a disposable battery are eventually used up. At that point the battery is dead and can no longer be used. Other batteries are rechargeable. A rechargeable battery can be inserted into a device that uses electric current to convert the product of the reaction back to the reactants. As a result, a rechargeable battery can be used over and over again.

What is an advantage of rechargeable batteries over disposable batteries?

A Rechargeable batteries have a lower initial purchase price.

B Rechargeable batteries produce a stronger electric current.

C Rechargeable batteries result in less pollution of the environment.

D Rechargeable batteries convert chemical energy directly to electricity.

A

B

C

D

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