9-12 chem test 731 - wikispaces · pdf file2 ©2007 the president and fellows of harvard...

CHEMISTRY TEST

1

©2007 The President and Fellows of Harvard College. Project MOSART, NSF 0412382. Test Form 731.

For some questions, there may be more than one correct answer. However, each question has only onebest answer. Choose the single best answer from the five choices for each question.

1. The chemical reaction of photosynthesis naturally occurs in the presence of sunlight because the light:a. is one of the reactants.b. helps oxygen to “see” carbon dioxide.c. vaporizes water.d. provides the energy to start the reaction.e. brings the oxygen into the plant.

2. What general shape will CCl4 most likely have?a. Linearb. Trigonal planar (triangle)c. Tetrahedrald. Trigonal pyramide. V-shaped

3. Of the following, which are linked to chemical reactions in humans?a. Digestionb. Tastec. Visiond. a and be. a, b, and c

4. What is in between the electrons and nucleus of an atom?a. Nothingb. Airc. Water vapord. Smaller atomse. No one knows.

5. Chemists say that when these two atoms react the Na outer electron is:

Na Cl

a. shared.b. transferred.c. combined.d. destroyed.e. subtracted.

GO TO QUESTION 6 >>

2


6. The charge in a nucleus of an atom is:a. neutral.b. negative.c. positive.d. continuously changing.e. not possible to determine.

7. The rightmost column of the Periodic Table includes the noble gases, all of which:a. are lighter than air.b. are never liquid or solid at any temperature.c. are found only in Earth’s atmosphere.d. are missing one electron in their outer orbital.e. have filled electron shells.

8. Which of the compounds below is most likely to have a dipole moment (be polar)?

O C O

O

H HH F

1. 2. 3.

a. 1b. 2c. 3d. 1 and 3e. 1, 2 and 3

9. If you were to hammer some gold into a thin sheet, the atoms:a. would each flatten out.b. weigh less.c. are pushed closer together.d. are unchanged.e. None of the above.

10. A portion of the Periodic Table is shown below.

N O

P S

Which element(s) has exactly one more outermost electron than element N?a. Only O.b. Only P.c. O and S.d. All of the other elements have exactly one more outermost electron than element N.e. None of the other elements has exactly one more outermost electron than element N.

3


11. Which of the equations below best represents atoms in a fusion reaction?

energya.

b.

energyc.

energyd.

e. energy

energy

12. A sample of which of the following substances contains some kind of bond?a. Copperb. Carbon monoxidec. Neitherd. Bothe. It depends on the isotope ratio.

13. When water goes from solid to liquid, the distances between the three atoms within a molecule:a. get larger.b. get smaller.c. don’t change.d. don’t change between H and O, but the angle between hydrogens is larger.e. don’t change between H and O, but the angle between hydrogens is smaller.

14. The isomers of pentane always have the same:a. structure.b. color.c. formula.d. melting point.e. boiling point.

15. Following a nuclear reaction that releases energy, the total particle mass is:a. is slightly more than the original.b. is the same as the original.c. is slightly less than the original.d. is zero since it was completely consumed.e. twice as much as the original.

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16. The Periodic Table is arranged according to the:a. number of protons in each element's atoms.b. color of each element.c. melting point of each element.d. phase of the element at room temperature.e. order in which the elements were discovered.

17. The diagram below shows the reaction between hydrogen and iodine.

170 kJ

13kJ2 Hl

Time

Energy

H2+ l

2

The reaction between hydrogen and iodine to form hydrogen iodide:a. absorbs heat energy.b. releases heat energy.c. absorbs and releases equal amounts of heat energy.d. does not involve heat energy.e. More information is needed.

18. Enzymes in your body will:a. increase the chance that two different molecules will touch and react with each other.b. make it possible to react outside of a cell.c. make it possible to react more slowly, so that all collisions are effective.d. change the purpose of a reaction.e. replace one reacting species to create a similar product, but faster.

19. One isotope of oxygen differs from another isotope of oxygen in:a. the number of protons.b. the number of electrons.c. the mass.d. two of the above.e. all of the above.

20. If the nucleus of an atom was left undisturbed for several years, which of the following would most likelyhappen?a. Electrons would collide with the protons in the nucleus.b. Protons would lose their charge.c. The neutrons would become electrically charged.d. Some protons and neutrons would merge together.e. Nothing.

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21. Which of the following best describes a sample of a radioactive element?a. It is very dangerous.b. It changes into a different element as time goes by.c. It always generates the same amount of radioactivity over time.d. It is artificial.e. It could only have existed since the mid twentieth century.

22. Atoms can interact with one another by sharing:a. protons.b. neutrons.c. electrons.d. nuclei.e. isotopes.

CHEMISTRY TEST

1


For some questions, there may be more than one correct answer. However, each question has only onebest answer. Choose the single best answer from the five choices for each question.

1. The Periodic Table is arranged according to the:a. number of protons in each element's atoms.b. color of each element.c. melting point of each element.d. phase of the element at room temperature.e. order in which the elements were discovered.

2. If the nucleus of an atom was left undisturbed for several years, which of the following would most likelyhappen?a. Electrons would collide with the protons in the nucleus.b. Protons would lose their charge.c. The neutrons would become electrically charged.d. Some protons and neutrons would merge together.e. Nothing.

3. A portion of the Periodic Table is shown below.

N O

P S

Which element(s) has exactly one more outermost electron than element N?a. Only O.b. Only P.c. O and S.d. All of the other elements have exactly one more outermost electron than element N.e. None of the other elements has exactly one more outermost electron than element N.

4. The isomers of pentane always have the same:a. structure.b. color.c. formula.d. melting point.e. boiling point.

5. Enzymes in your body will:a. increase the chance that two different molecules will touch and react with each other.b. make it possible to react outside of a cell.c. make it possible to react more slowly, so that all collisions are effective.d. change the purpose of a reaction.e. replace one reacting species to create a similar product, but faster.

2


GO TO QUESTION 6 >>6. Following a nuclear reaction that releases energy, the total particle mass is:

a. is slightly more than the original.b. is the same as the original.c. is slightly less than the original.d. is zero since it was completely consumed.e. twice as much as the original.

7. Which of the following best describes a sample of a radioactive element?a. It is very dangerous.b. It changes into a different element as time goes by.c. It always generates the same amount of radioactivity over time.d. It is artificial.e. It could only have existed since the mid twentieth century.

8. The diagram below shows the reaction between hydrogen and iodine.

170 kJ

13kJ2 Hl

Time

Energy

H2+ l

2

The reaction between hydrogen and iodine to form hydrogen iodide:a. absorbs heat energy.b. releases heat energy.c. absorbs and releases equal amounts of heat energy.d. does not involve heat energy.e. More information is needed.

9. One isotope of oxygen differs from another isotope of oxygen in:a. the number of protons.b. the number of electrons.c. the mass.d. two of the above.e. all of the above.

10. Of the following, which are linked to chemical reactions in humans?a. Digestionb. Tastec. Visiond. a and be. a, b, and c

3


11. Atoms can interact with one another by sharing:a. protons.b. neutrons.c. electrons.d. nuclei.e. isotopes.

12. What general shape will CCl4 most likely have?a. Linearb. Trigonal planar (triangle)c. Tetrahedrald. Trigonal pyramide. V-shaped

13. If you were to hammer some gold into a thin sheet, the atoms:a. would each flatten out.b. weigh less.c. are pushed closer together.d. are unchanged.e. None of the above.

14. The charge in a nucleus of an atom is:a. neutral.b. negative.c. positive.d. continuously changing.e. not possible to determine.

15. Chemists say that when these two atoms react the Na outer electron is:

Na Cl

a. shared.b. transferred.c. combined.d. destroyed.e. subtracted.

16. What is in between the electrons and nucleus of an atom?a. Nothingb. Airc. Water vapord. Smaller atomse. No one knows.

4


17. Which of the equations below best represents atoms in a fusion reaction?

energya.

b.

energyc.

energyd.

e. energy

energy

18. Which of the compounds below is most likely to have a dipole moment (be polar)?

O C O

O

H HH F

1. 2. 3.

a. 1b. 2c. 3d. 1 and 3e. 1, 2 and 3

19. When water goes from solid to liquid, the distances between the three atoms within a molecule:a. get larger.b. get smaller.c. don’t change.d. don’t change between H and O, but the angle between hydrogens is larger.e. don’t change between H and O, but the angle between hydrogens is smaller.

20. A sample of which of the following substances contains some kind of bond?a. Copperb. Carbon monoxidec. Neitherd. Bothe. It depends on the isotope ratio.

5


GO TO QUESTION 21 >>21. The chemical reaction of photosynthesis naturally occurs in the presence of sunlight because the light:

a. is one of the reactants.b. helps oxygen to “see” carbon dioxide.c. vaporizes water.d. provides the energy to start the reaction.e. brings the oxygen into the plant.

22. The rightmost column of the Periodic Table includes the noble gases, all of which:a. are lighter than air.b. are never liquid or solid at any temperature.c. are found only in Earth’s atmosphere.d. are missing one electron in their outer orbital.e. have filled electron shells.

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Grades 9–12 Chemistry Tests

The tests in this section contain items related to 12 of the grades 9�–12 standardsin physical science related to chemistry from the NRC's National Science EducationStandards (NSES); below are the standards as stated in the NSES.

9–12 Chemistry Standard 1:"Matter is made of minute particles called atoms, and atoms are composed ofeven smaller components. These components have measurable properties, suchas mass and electrical charge. Each atom has a positively charged nucleussurrounded by negatively charged electrons. The electric force between thenucleus and electrons holds the atom together."

9–12 Chemistry Standard 2:"The atom's nucleus is composed of protons and neutrons, which are much moremassive than electrons. When an element has atoms that differ in the number ofneutrons, these atoms are called different isotopes of the element."

9–12 Chemistry Standard 3:"The nuclear forces that hold the nucleus of an atom together, at nucleardistances, are usually stronger than the electric forces that would make it flyapart. Nuclear reactions convert a fraction of the mass of interacting particles intoenergy, and they can release much greater amounts of energy than atomicinteractions. Fission is the splitting of a large nucleus into smaller pieces. Fusionis the joining of two nuclei at extremely high temperature and pressure, and isthe process responsible for the energy of the sun and other stars."

9–12 Chemistry Standard 4:"Radioactive isotopes are unstable and undergo spontaneous nuclear reactions,emitting particles and/or wavelike radiation. The decay of any one nucleuscannot be predicted, but a large group of identical nuclei decay at a predictablerate. This predictability can be used to estimate the age of materials that containradioactive isotopes."

9–12 Chemistry Standard 5:"Atoms interact with one another by transferring or sharing electrons that arefurthest from the nucleus. These outer electrons govern the chemical propertiesof the element."

9–12 Chemistry Standard 6:"An element is composed of a single type of atom. When elements are listed inorder according to the number of protons (called the atomic number), repeatingpatterns of physical and chemical properties identify families of elements withsimilar properties. This "Periodic Table" is a consequence of the repeating patternof outermost electrons and their permitted energies."

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9–12 Chemistry Standard 7:"Bonds between atoms are created when electrons are paired up by beingtransferred or shared. A substance composed of a single kind of atom is called anelement. The atoms may be bonded together into molecules or crystalline solids.A compound is formed when two or more kinds of atoms bind togetherchemically."

9–12 Chemistry Standard 8:"The physical properties of compounds reflect the nature of the interactionsamong its molecules. These interactions are determined by the structure of themolecule, including the constituent atoms and the distances and angles betweenthem."

9–12 Chemistry Standard 9:�“Carbon atoms can bond to one another in chains, rings, and branching networksto form a variety of structures, including synthetic polymers, oils, and the largemolecules essential to life."

9–12 Chemistry Standard 10:"Chemical reactions occur all around us, for example in health care, cooking,cosmetics, and automobiles. Complex chemical reactions involving carbon-basedmolecules take place constantly in every cell in our bodies."

9–12 Chemistry Standard 11:"Chemical reactions may release or consume energy. Some reactions such as theburning of fossil fuels release large amounts of energy by losing heat and byemitting light. Light can initiate many chemical reactions such as photosynthesisand the evolution of urban smog."

9–12 Chemistry Standard 12:"Catalysts, such as metal surfaces, accelerate chemical reactions. Chemicalreactions in living systems are catalyzed by protein molecules called enzymes."

The items are identical on both test forms, but arranged in different sequences sothat the forms can be used as a pretest/post-test pair (either form may be used asthe pretest). Either form can be used by itself as a diagnostic test.

The 9�–12 tests are intended for use primarily with high school chemistrystudents. The tests can also be administered to any persons who possess at least a9th grade reading level fluency in English.

NOTE: Administering the tests to anyone with less than the indicated minimumreading level may result in invalid test results due to the test performing more asa reading comprehension test rather than as a science test.

3

Item #

Form

731

Item #

Form

732

Text of Item Std. 1

Correct

response &

percent

responding

correctly2

Commentary3

1 21

The chemical reaction ofphotosynthesis naturallyoccurs in the presence ofsunlight because the light:a. is one of the reactants.b. helps oxygen to “see”

carbon dioxide.c. vaporizes water.d. provides the energy to

start the reaction.e. brings the oxygen into

the plant.

11 D: 79%

(n=3700)

A large majority ofstudents respondedcorrectly to this item. Noincorrect option wassignificantly more popularthan the others, with5–10% of studentschoosing each.

2 12

What general shape willCCl4 most likely have?a. Linearb. Trigonal planar

(triangle)c. Tetrahedrald. Trigonal pyramide. V-shaped

8 C: 54%

(n=1000)

The most popularincorrect response was A,with 25% of studentsindicating that thecompound would have alinear shape.

3 10

Of the following, which arelinked to chemicalreactions in humans?a. Digestionb. Tastec. Visiond. a and be. a, b, and c

10 E: 20%

(n=1219)

40% of students correctlyidentified digestion as aprocess involvingchemical reactions (A).Another 34% chose D(digestion and taste). Fewstudents realize that thereare also chemicalreactions involved withvision, but this may be aresult of coverage.

What is in between theelectrons and nucleus of

A very commonmisconception is that

1 These test items are valid psychometrically and represent standards commonly included in grades 9�–12

chemistry curricula. Please note: The items do not represent the entire domain of standards as presented in

the NRC standards.

2 Students were selected randomly in classes as a nationally representative sample of all grades 9�–12

students in U.S. public and private schools. The sample number (n) is included for each response because

the number of students per item varied considerably.

3 The commentary reflects item response patterns. Common misconceptions in chemistry are discussed in a

separate section.

4

Item #

Form

731

Item #

Form

732

Text of Item Std. 1

Correct

response &

percent

responding

correctly2

Commentary3

4 16

an atom?a. Nothingb. Airc. Water vapord. Smaller atomse. No one knows.

1 A: 40%

(n=269)

“something” must existbetween an atom’snucleus and its electrons;the space cannot beempty. Reflecting thatidea, 21% of studentschose B. But 23% choseE.

5 15

Chemists say that whenthese two atoms react theNa outer electron is:(see figure in item on test)a. shared.b. transferred.c. combined.d. destroyed.e. subtracted.

5 B: 26%

(n=577)

Only about one-fourth ofstudents answered thisitem correctly. Slightlymore than 50% chose A,suggesting that moststudents think nearlyevery bond is strictlycovalent.

6 14

The charge in a nucleus ofan atom is:a. neutral.b. negative.c. positive.d. continuously changing.e. not possible to

determine.

2 C: 30%

(n=1447)

As many students chose Aas chose the correctanswer, which suggestsstudents have problemsrelated to nuclearstructure.

7 22

The rightmost column ofthe Periodic Tableincludes the noble gases,all of which:a. are lighter than air.b. are never liquid or

solid at anytemperature.

c. are found only inEarth’s atmosphere.

d. are missing oneelectron in their outerorbital.

e. have filled electronshells.

6 E: 71%

(n=485)

Few students respondedincorrectly to this item onthe Periodic Table. Asmall number (12%)chose B. The otheroptions were chosen byfewer than 10% each.

Which of the compoundsbelow is most likely tohave a dipole moment (bepolar)? (See figures initem on test.)

This item requiredstudents to apply theirunderstanding of polarityto three molecules. Themost popular choice was

5

Item #

Form

731

Item #

Form

732

Text of Item Std. 1

Correct

response &

percent

responding

correctly2

Commentary3

8 18

a. 1b. 2c. 3d. 1 and 3e. 1, 2 and 3 8

D: 21%

(n=576)

water as the only polarsubstance with 40% ofstudents choosing thatresponse (C). The secondmost frequent responsewas B (22%). This patternsuggests that manystudents relate polarityonly with asymmetricalmolecular structure.

9 13

If you were to hammersome gold into a thinsheet, the atoms:a. would each flatten out.b. weigh less.c. are pushed closer

together.d. are unchanged.e. None of the above.

1 D: 38%

(n=891)

This item is an example ofa very commonmisconception, i.e., thatthe macroscopic behaviorof a material and of theatoms that make up thematerial are the same.The most popularincorrect response waschoice C (32%).

10 3

A portion of the PeriodicTable is shown below.(See figure in item ontest.) Which element(s)has exactly one moreoutermost electron thanelement N?a. Only O.b. Only P.c. O and S.d. All of the other

elements have exactlyone more outermostelectron than elementN.

e. None of the otherelements has exactlyone more outermostelectron than elementN.

8 C: 30%

(n=552)

This item requires analysisas well as knowledge ofthe Periodic Table toanswer correctly. Fewerthan one third of studentswere able to correctlycarry out this process. Anequal number chose A.This response patternmight indicate a lack ofunderstanding of therelationship betweenposition on the PeriodicTable and the electronstructure of elements atthe atomic level.

6

Item #

Form

731

Item #

Form

732

Text of Item Std. 1

Correct

response &

percent

responding

correctly2

Commentary3

11 17

Which of the equationsbelow best representsatoms in a fusionreaction? (See figures initem on test.)

3 A: 30%

(n=890)

The most popularresponse was D, chosenby 45% of students. Theillustration for D suggestsa chemical reaction thatreleases energy,suggesting that manystudents cannotdistinguish betweennuclear and chemicalreactions.

12 20

A sample of which of thefollowing substancescontains some kind ofbond?a. Copperb. Carbon monoxidec. Neitherd. Bothe. It depends on the

isotope ratio.

8 D: 21%

(n=528)

The pattern of responsesto this question reveal thatmany students do notgrasp the notion thatelements (such as copper)have bonds between theatoms, just as betweenmolecules that make upcompounds. 67% ofstudents chose B, anobvious molecule.

13 19

When water goes fromsolid to liquid, thedistances between thethree atoms within amolecule:a. get larger.b. get smaller.c. don’t change.d. don’t change between

H and O, but the anglebetween hydrogens islarger.

e. don’t change betweenH and O, but the anglebetween hydrogens issmaller.

8 C: 20%

(n=703)

The misunderstanding ofthe relationship betweenmacroscopic changes andmicroscopic particles isagain illustrated by thisitem. The most frequentlychosen response was A(49%). Also, 20% of thestudents chose B,revealing this commonmisconception.

14 4

The isomers of pentanealways have the same:a. structure.b. color.c. formula.d. melting point.e. boiling point.

9 C: 39%

(n=890)

Interestingly, choice A wasthe second most frequentresponse after the correctone; 36% indicated thatthe structure was thesame for the isomers ofpentane, the characteristicthat defines one ofdifferences betweenisomers.

7

Item #

Form

731

Item #

Form

732

Text of Item Std. 1

Correct

response &

percent

responding

correctly2

Commentary3

15 6

Following a nuclearreaction that releasesenergy, the total particlemass is:a. is slightly more than

the original.b. is the same as the

original.c. is slightly less than the

original.d. is zero since it was

completely consumed.e. twice as much as the

original.

3 C: 46%

(n=1454)

26% of students chose B,suggesting that studentsdo not understand therelationship betweennuclear reactions andmass. They may confusenuclear reactions andchemical reactions, inwhich total mass does notchange.

16 1

The Periodic Table isarranged according to the:a. number of protons in

each element's atoms.b. color of each element.c. melting point of each

element.d. phase of the element

at room temperature.e. order in which the

elements werediscovered.

6 A: 89%

(n=674)

A large majority ofstudents respondedcorrectly. Less than 4% ofstudents chose any one ofthe incorrect options,suggesting a random“guessing” pattern.

178

The reaction betweenhydrogen and iodine toform hydrogen iodide (seediagram in item on test):a. absorbs heat energy.b. releases heat energy.c. absorbs and releases

equal amounts of heatenergy.

d. does not involve heatenergy.

e. More information isneeded.

11 B: 52%

(n=925)

Interestingly, while abouthalf of the students chosethe correct response, theanswer chosen next mostfrequently (21%) was A.This pattern suggests thatstudents may havedifficulty in readinggraphs. Choice C drew a14% response, while Eattracted 10% and D only3%.

8

Item #

Form

731

Item #

Form

732

Text of Item Std. 1

Correct

response &

percent

responding

correctly2

Commentary3

18 5

Enzymes in your body will:a. increase the chance

that two differentmolecules will touchand react with eachother.

b. make it possible toreact outside of a cell.

c. make it possible toreact more slowly, sothat all collisions areeffective.

d. change the purpose ofa reaction.

e. replace one reactingspecies to create asimilar product, butfaster.

12 A: 40%

(n=296)

Although the correctresponse was chosenmost frequently, some20% of students choseeither C or E. As enzymesare a type of catalyst, thispattern is consistent withthe performance on allitems addressing catalystsof all sorts observed in ournationwide field trials.

19 9

One isotope of oxygendiffers from anotherisotope of oxygen in:a. the number of protons.b. the number of

electrons.c. the mass.d. two of the above.e. all of the above.

2 C: 27%

(n=267)

Choice D was chosen byan equal number ofstudents (27%) as was thecorrect response. Notethat this response couldmean students had both Aand B in mind, or A and C,or B and C.

20 2

If the nucleus of an atomwas left undisturbed forseveral years, which of thefollowing would most likelyhappen?a. Electrons would collide

with the protons in thenucleus.

b. Protons would losetheir charge.

c. The neutrons wouldbecome electricallycharged.

d. Some protons andneutrons would mergetogether.

e. Nothing.

2 E: 64%

(n=576)

No more than 10% of thestudents in the samplechose any given incorrectoption. Again, this patternimplies guessing bystudents who did not knowthe answer, with no strongmisconception dominating.

9

Item #

Form

731

Item #

Form

732

Text of Item Std. 1

Correct

response &

percent

responding

correctly2

Commentary3

21 7

Which of the followingbest describes a sampleof a radioactive element?a. It is very dangerous.b. It changes into a

different element astime goes by.

c. It always generates thesame amount ofradioactivity over time.

d. It is artificial.e. It could only have

existed since the midtwentieth century.

4 B: 20%

(n=890)

Two incorrect optionswere more frequentlychosen by students thanthe correct response.48% indicated thatradioactive elements arevery dangerous (A),regardless of the mass ofthe sample or the elementcomposing it since neitherof these features ismentioned. Clearly thedangerous nature ofradioactive materials hasbeen the messageabsorbed by students,perhaps from the media.Choice C was chosen by23%, which reveals amore subtle error inreasoning aboutradioactive decay.

22 11

Atoms can interact withone another by sharing:a. protons.b. neutrons.c. electrons.d. nuclei.e. isotopes.

5 C: 80%

(n=579)

Students who respondedincorrectly to this questiongenerally chose A, but thisis such a small number(9%), it is reasonable toconclude that studentsguessed if they didn’tknow the correctresponse.

Major Misconceptions in Grades 9–12 Chemistry

Listed below are some student chemistry misconceptions. The list is not intendedto be exhaustive, but rather a summary of some of the more common prior ideaswe identified from our analysis of the student response patterns to the items onthe tests.

�• No space is completely empty, both within atoms (as between nuclei andelectron clouds) or between particles in solids, liquids or gases.

�• All bonds involve equal sharing of electron pairs.

�• There are no bonds in elementary substances, e.g., in a piece of pure gold.

10

�• Particles are mini-versions of the substances they comprise and possess thesame properties.

�• The expansion or contraction of matter is due to corresponding changes in theconstituent particles, and not the space between the particles.

�• Only asymmetrical molecules can be polar.

�• All radioactivity is dangerous to humans, regardless of source, type orduration of exposure.

The following resources are useful for additional background information aboutstudents' science misconceptions:

Driver, R., Pupil as Scientist?, Philadelphia: Open University Press (1983).

Driver, R., et al., Making Sense of Secondary Science, Philadelphia: Open UniversityPress (1994).

Wandersee, J.H., et al., �“Research on Alternative Conceptions in Science,�” inGabel, D., (ed.) Handbook of Research on Science Teaching and Learning, NewYork: Macmillan, pp. 177�–210 (1994).

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