ACT Science : Earth and Space Sciences

Study concepts, example questions & explanations for ACT Science

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Example Questions

Example Question #18 : How To Find Experimental Design In Earth And Space Sciences

One night there was a meteor shower and scientists in four different regions, A, B, C and D, observed and counted the number of meteors seen. The scientists noted the duration of the meteor shower and the visibility of the stars. 

Act 2

What is a way that the scientists could improve their method of observation? 

Possible Answers:

Note if the observations were taken by the naked eye or by an automated telescope

Note the elevation of each observation location

All of these

Note the weather and the potential impact this had on their observations

Determine the light pollution in each region and how this impacts results

Correct answer:

All of these

Explanation:

The weather in a region could impact the results if it were cloudy or if it was clearly would change visibility. Knowing the weather would improve the results of this experiments validity. Using an automated telescope would prevent human error that could occur in observations made by the naked eye. Light pollution affects the visibility of the night sky. Also, noting the elevation of the locations may affect visibility of meteors. Knowing this information will inform one how the light pollution affects the results of the observation.

Example Question #1001 : Act Science

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:

Different drills can be used for land and underwater

The amount of oil that can be obtained at each site

All of these

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

The cost of operating on land versus 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 #1002 : 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:

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

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

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

Cannot be determined from the given information

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 #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

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:

II and III

I 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 #72 : 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:

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

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

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

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.

Example Question #71 : Earth And Space Sciences

Since the early 1900s, there has been a steady increase in the earth’s atmospheric temperature, resulting in a phenomenon called “Global Warming.” While the steady temperature change has been well documented, the cause of global warming remains controversial.

Scientist 1

Scientist 1 believes that “external forcings” are the cause of increased temperature over the past century. “External forcings” can direct the change in temperature over thousands of years. One example of an external force is variation in the earth’s orbit around the sun. The earth orbital cycle lasts 26,000 years and causes general trends in warming and cooling.

Scientist 2

Scientist 2 believes that global warming is a man-made phenomenon due to an increase in greenhouse gases such as carbon dioxide or methane. Greenhouse gases have a natural warming effect, however, an increase in the amount of atmospheric greenhouse gases many enhance that effect. Since 1750, the concentration of carbon dioxide has increased 36 percent while the amount of atmospheric methane has increased 148 percent.

What data supports Scientist 2's theory?

Possible Answers:

A graph depicting a positive correlation between the concentration of greenhouse gases and average atmospheric temperature

A graph depicting a negative correlation between the number of humans on earth and the average atmospheric temperature

A graph depicting a negative correlation between the concentration of greenhouse gases and average atmospheric temperature

A graph depicting a postive correlation between the number of humans on earth and the average atmospheric temperature

Correct answer:

A graph depicting a positive correlation between the concentration of greenhouse gases and average atmospheric temperature

Explanation:

Because increased temperature is attributed to an increase in greenhouse gases, a graph depicting a postive correlation between the two is suggestive of a relationship between increased production of greenhouse gases and global warming.

Example Question #2 : How To Find Synthesis Of Data In Earth And Space Sciences

Since the early 1900s, there has been a steady increase in the earth’s atmospheric temperature, resulting in a phenomenon called “Global Warming.” While the steady temperature change has been well documented, the cause of global warming remains controversial.

Scientist 1

Scientist 1 believes that “external forcings” are the cause of increased temperature over the past century. “External forcings” can direct the change in temperature over thousands of years. One example of an external force is variation in the earth’s orbit around the sun. The earth orbital cycle lasts 26,000 years and causes general trends in warming and cooling.

Scientist 2

Scientist 2 believes that global warming is a man-made phenomenon due to an increase in greenhouse gases such as carbon dioxide or methane. Greenhouse gases have a natural warming effect, however, an increase in the amount of atmospheric greenhouse gases many enhance that effect. Since 1750, the concentration of carbon dioxide has increased 36 percent while the amount of atmospheric methane has increased 148 percent.

What is a potential cause for an increase in greenhouse gases since 1750?

Possible Answers:

An increase in gas released from melting ice caps

An increase in clorofluorocarbons resulting in depletion of the ozone layer

An increase in the number of plants producing carbon dioxide

Production of greenhouse gases during the industrial revolution and population growth

Correct answer:

Production of greenhouse gases during the industrial revolution and population growth

Explanation:

During the early 1900s, the Industrial Revolution resulted in burning coal for energy, which caused an increase in production of greenhouse gases. Additionally, the increase in population has caused rapid deforestation, reducing the number of plants and trees that consume carbon dioxide. To date, there is no strong link between depletion of the ozone layer and climate change.

Example Question #3 : How To Find Synthesis Of Data In Earth And Space Sciences

Since the early 1900s, there has been a steady increase in the earth’s atmospheric temperature, resulting in a phenomenon called “Global Warming.” While the steady temperature change has been well documented, the cause of global warming remains controversial.

Scientist 1

Scientist 1 believes that “external forcings” are the cause of increased temperature over the past century. “External forcings” can direct the change in temperature over thousands of years. One example of an external force is variation in the earth’s orbit around the sun. The earth orbital cycle lasts 26,000 years and causes general trends in warming and cooling.

Scientist 2

Scientist 2 believes that global warming is a man-made phenomenon due to an increase in greenhouse gases such as carbon dioxide or methane. Greenhouse gases have a natural warming effect, however, an increase in the amount of atmospheric greenhouse gases many enhance that effect. Since 1750, the concentration of carbon dioxide has increased 36 percent while the amount of atmospheric methane has increased 148 percent.

In the year 2438 another ice age occurs, supporting which scientists' theory?

Possible Answers:

Both Scientists

Scientist 1

Neither Scientist

Scientist 2

Correct answer:

Scientist 1

Explanation:

Scientist 1 believes that global warming is a result of cyclical changes in the earth's orbit; therefore, periods of global warming should be followed by periods of global cooling, which can result in another ice age. On the other hand, Scientist 2 believes that as the world's population continues to grow, global warming will also continue. Because there was no data presented to suggest an abrupt change in population growth, scientist 2's theory is incorrect.

Example Question #72 : Earth And Space Sciences

Since the early 1900s, there has been a steady increase in the earth’s atmospheric temperature, resulting in a phenomenon called “Global Warming.” While the steady temperature change has been well documented, the cause of global warming remains controversial.

Scientist 1

Scientist 1 believes that “external forcings” are the cause of increased temperature over the past century. “External forcings” can direct the change in temperature over thousands of years. One example of an external force is variation in the earth’s orbit around the sun. The earth orbital cycle lasts 26,000 years and causes general trends in warming and cooling.

Scientist 2

Scientist 2 believes that global warming is a man-made phenomenon due to an increase in greenhouse gases such as carbon dioxide or methane. Greenhouse gases have a natural warming effect, however, an increase in the amount of atmospheric greenhouse gases many enhance that effect. Since 1750, the concentration of carbon dioxide has increased 36 percent while the amount of atmospheric methane has increased 148 percent.

In the year 2150, the United Nations institutes a global limit on the production of greenhouse gases. The average atmospheric temperature continues to increase, although the rate of increase is less than it was before 2150. Does this invalidate the theory proposed by Scientist 2? Why or why not?

Possible Answers:

No; Increased population may have indirect effects on the concentration of greenhouse gases that can not be regulated.

Yes; Limiting greenhouse gas production does not solve the issue of global warming.

No; A limitation on the production of greenhouses gases will not have an effect on global warming.

Yes; If Scientist 2's theory was correct, the atmospheric temperature would not continue to rise.

Correct answer:

No; Increased population may have indirect effects on the concentration of greenhouse gases that can not be regulated.

Explanation:

Because there is a modest change in temperature and increased greenhouse gas concentrations can not be ruled out (through mechanisms such as deforestation), we can not conclude that Scientist 2's theory was correct.

Example Question #73 : Earth And Space Sciences

The significant increase in atmospheric carbon dioxide since pre-industrial levels can be seen in the world’s oceans which absorb the CO2 and in turn undergo changes in chemistry. The consequences of increased CO2 include acidification of seawater and a decrease in carbonate ion (CO32-) concentration. 

Changes in seawater chemistry affect marine organisms. The early life stages of invertebrates, such as squid, may be particularly vulnerable to changes in carbon dioxide levels. Acting as both predator and prey, squid are a significant component of marine ecosystems.   For example, fish and sea birds, such as tuna and albatross, are dependent on squid as a source of prey. Furthermore, the fishing industry is impacted by the health of squid populations. California fisheries produce the majority of market squid.

In order to determine how increased levels of carbon dioxide affect the development of squid, eggs were hatched in two different conditions: normal (380 µatm) and elevated (2100 µatm) levels of CO2. The time to hatch and the size of the larval mantle (the anatomical feature that includes the body wall and fins) were measured and recorded. Two trials were conducted for each carbon dioxide concentration.

 

Charts
Graphs

 

The results of this experiment show that ________.

Possible Answers:

Lower marine pH levels reduce the hatching time of squid

Higher levels of marine carbon dioxide reduce the size of tuna

Higher levels of atmospheric carbon dioxide reduce the size of squid

Lower marine pH levels increase the size of squid

Correct answer:

Higher levels of atmospheric carbon dioxide reduce the size of squid

Explanation:

The only correct correlation given is that increased carbon dioxide levels reduce the size of the squid.  Data for tuna size is not given.  As for correlation with pH, lower pH levels correspond to increased  hatching time of squid and a decrease in the size of squid.  

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