ACT Science : How to find experimental design in earth and space sciences

Study concepts, example questions & explanations for ACT Science

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Example Questions

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Example Question #71 : Earth And Space Sciences

Scientist 1: This scientist asserts that drilling for oil should be performed in the ocean. Scientist 1 claims that in the ocean, the oil is at a shorter depth below the Earth’s surface than on dry land. The shorter drilling depth is more ideal for access by drills.

Scientist 2: Scientist 2 believes that drilling for oil should be performed on dry land and not underwater. This is due to the fact that water is at a higher pressure than is observed on the surface of Earth. Scientist 2 asserts that drilling at the lower pressure will be less likely to damage the equipment resulting in an unsuccessful event.

Experiment: The scientists conduct various experiments. The data that the scientists collect indicates the depth at which it is necessary to drill on land and in the ocean in order to reach. The other data that the scientist collect is on the pressure that the equipment will need to experience while drilling for oil at each location.

What is not taken into account with the information that the scientists obtain in their experiments? 

Possible Answers:

The amount of oil that can be obtained at each site

The time it would take to drill to the appropriate depth at each site

All of these

The cost of operating on land versus underwater

Different drills can be used for land and underwater

Correct answer:

All of these

Explanation:

Drills are made to used on land and there are also drills that are made to be used underwater. Operating costs are a necessary requirement to determine the best location to drill at for the maximum profits. The scientist do not consider the oil that can be yielded at each site, which could change the best location to drill at. Finally, the scientist measure the depth to drill at, but there is no indication if it takes longer to drill underwater than on land or vice versa. The scientists should long into all of this information.  

Example Question #1001 : Act Science

Scientist 1: Scientist 1 claims that the best spot to find gold is near volcanic areas. This scientist claims that the high temperatures and high pressure helps to form the gold. Therefore the best area to find large quantities of gold is near volcanoes.

Scientist 2: Scientist 2 asserts that the best area to find gold is in rivers. In the rivers the gold can be free flowing and easier to see. In addition, the gold found in the rivers does not necessarily require equipment for digging. It is is found in the river due to the water carrying, rather than eroding it. 

How can it be determined which scientist's site is the best to find gold? 

Possible Answers:

Cannot be determined from the given information

Dig only a single hole near the volcano and only look at one river then compare the obtained data

The scientists can guess at the best location and search for gold there

Ask locals of both regions how much gold they believe can be found in each location

The scientists can ask a geologist for the best location

Correct answer:

Dig only a single hole near the volcano and only look at one river then compare the obtained data

Explanation:

The scientists should not ask the locals or a geologist, but should perform experiments themselves to obtain primary data. The scientists can perform a smaller dig site at the volcano and a smaller scale look at the rivers to determine the best location before performing a full scale digging experiment. 

Example Question #1001 : Act Science

Scientists have long debated the origin of organic molecules on Earth. Organic molecules are those based on the atom carbon, which can form four distinct bonds in contrast to the fewer number allowed in most other non-metals. As a result of this property, carbon can give rise to the enormously complex molecular shapes necessary for life to arise.

Some scientists argue that organic matter was dissolved in water ice on comets, and brought to Earth early in its history. These comets crashed into the early Earth, and deposited carbon-based molecules in copious quantities to the Earth’s surface as their water melted.

In 2014, the first space probe landed on the comet 67P/Churyumov-Gerasimenko. Suppose that scientists find the following information from 5 distinct samples after landing on the comet. Each sample was taken at a single geographical location, but 5 meters deeper than the last. Sample 1 was taken at a depth of 1 meter below the surface.

Sample #

Water Ice?

Concentration of Organics

1

No

N/A

2

Yes

1 mg/L

3

No

N/A

4

Yes

4 mg/L

5

Yes

10 mg/L

These samples were compared to 5 similar samples from the surface of Mars. Scientists posited that this comparison would be meaningful because we know that life does not exist on Mars the same way that it does on Earth. Thus, they are comparing a known non-biological celestial body, Mars, with another celestial body, the comet, which may be seeding life on suitable plants.

Sample #

Water Ice?

Concentration of Organics

1

No

N/A

2

No

N/A

3

No

N/A

4

No

N/A

5

Yes

1 mg/L

The use of multiple samples on both the comet and Mars is most likely used to:

I.  Compare different geographical regions on both the comet and Mars, as measured for the concentration of organics

II.  Help determine the consistency of measurements taken by the instruments

III.  Ascertain how depth of sampling impacts the concentration of organics

Possible Answers:

I and III

II and III

I and II

II only

Correct answer:

II and III

Explanation:

The passage specifies that the sampling is being completed in one location on both Mars and the comet. Thus, option I is not appropriate. Both II and III are valid reasons for using multiple measurements. These multiple measurements give us an idea of how consistent our measurement instruments are, as well as the overall trends that we are observing.

Example Question #71 : Earth And Space Sciences

Scientists have long debated the origin of organic molecules on Earth. Organic molecules are those based on the atom carbon, which can form four distinct bonds in contrast to the fewer number allowed in most other non-metals. As a result of this property, carbon can give rise to the enormously complex molecular shapes necessary for life to arise.

Some scientists argue that organic matter was dissolved in water ice on comets, and brought to Earth early in its history. These comets crashed into the early Earth, and deposited carbon-based molecules in copious quantities to the Earth’s surface as their water melted.

In 2014, the first space probe landed on the comet 67P/Churyumov-Gerasimenko. Suppose that scientists find the following information from 5 distinct samples after landing on the comet. Each sample was taken at a single geographical location, but 5 meters deeper than the last. Sample 1 was taken at a depth of 1 meter below the surface.

Sample #

Water Ice?

Concentration of Organics

1

No

N/A

2

Yes

1 mg/L

3

No

N/A

4

Yes

4 mg/L

5

Yes

10 mg/L

These samples were compared to 5 similar samples from the surface of Mars. Scientists posited that this comparison would be meaningful because we know that life does not exist on Mars the same way that it does on Earth. Thus, they are comparing a known non-biological celestial body, Mars, with another celestial body, the comet, which may be seeding life on suitable plants.

Sample #

Water Ice?

Concentration of Organics

1

No

N/A

2

No

N/A

3

No

N/A

4

No

N/A

5

Yes

1 mg/L

Which of the following would most directly undermine the major finding of this study?

Possible Answers:

Another location on the comet is found to have higher concentrations of organic molecules.

The detection equipment on the comet has a higher threshold for detecting organic molecules than the one on Mars.

The detection equipment on the comet was contaminated with organic molecules from Earth.

Another location on Mars is found to have lower levels of organic molecules.

Correct answer:

The detection equipment on the comet was contaminated with organic molecules from Earth.

Explanation:

The major message of the study depends on the observation that the comet has a higher concentration of organics than does Martian soil. As a result, if the detection equipment was contaminated, the measured organic molecules were actually brought to the comet from Earth.

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