A group of scientists wanted to investigate weather patterns in four cities across the United States. They conducted a series of experiments to look for similarities and differences among the four cities. The scientists measured wind speed and direction, amount of precipitation, and percentage of cloud cover for one week. Further explanation can be found below.

Experiment 1

Scientists measured wind speed using an anemometer at 15 different locations around each city. Measurements were taken at each location 3 times a day and then averaged to get a daily wind speed for each city. This was repeated every day for one week and the results were compiled into table 1.

Experiment 2

Scientists set up barometers at five locations in each city. At the end of each day, the precipitation levels in the five barometers were averaged to find the average daily precipitation and the results are compiled in Table 2.

Experiment 3

For the final experiment, scientists placed upward facing cameras atop the ten tallest buildings in each city. The cameras took one picture per hour. The scientists then used computer software to stitch together the images from all the cameras. The resulting meta-image was then analyzed with another computer program to find the percent of the sky covered by clouds. The results can be found in table 3.

Which of the following is an assumption made by the scientists during the design of these experiments?

A group of scientists wanted to investigate weather patterns in four cities across the United States. They conducted a series of experiments to look for similarities and differences among the four cities. The scientists measured wind speed and direction, amount of precipitation, and percentage of cloud cover for one week. Further explanation can be found below.

Experiment 1

Scientists measured wind speed using an anemometer at 15 different locations around each city. Measurements were taken at each location 3 times a day and then averaged to get a daily wind speed for each city. This was repeated every day for one week and the results were compiled into table 1.

Experiment 2

Scientists set up barometers at five locations in each city. At the end of each day, the precipitation levels in the five barometers were averaged to find the average daily precipitation and the results are compiled in Table 2.

Experiment 3

For the final experiment, scientists placed upward facing cameras atop the ten tallest buildings in each city. The cameras took one picture per hour. The scientists then used computer software to stitch together the images from all the cameras. The resulting meta-image was then analyzed with another computer program to find the percent of the sky covered by clouds. The results can be found in table 3.

Which of the following is supported by the data in Experiment 3?

The above chemical equation describes the dissociation of carbonic acid  into bicarbonate  and hydrogen ion . A chemistry student wants to study the behavior of carbonic acid, as it is a part of one of the most important physiological control systems in the human body.

When carbon dioxide  enters the blood in your body, it takes on the form of carbonic acid. Carbonic acid is in what we call "equilibrium" with bicarbonate ion and hydrogen ion. This equilibrium functions in the following manner: if more carbonic acid is present, more will dissociate into bicarbonate and hydrogen ion. On the other hand, if there is more bicarbonate and/or hydrogen ion, we say that equilibrium as shown in the above equation will "shift left" and more carbonic acid will be produced from bicarbonate and hydrogen.

To study this effect, the student obtains a mixture of carbonic acid, bicarbonate, and hydrogen ion. Next, the student conducts trials in which she adds a certain amount of one of the chemicals one at a time and then measures how the concentrations of each chemical change after each addition.

Which statement best explains why it is important for the student to add each chemical one at a time before measuring the total concentrations and then adding a different chemical?

Glaciers move, on average, 1 meter per day, although many are known to move faster or slower depending on their size. Whether they are alpine glaciers, which form high in the mountains, or continental glaciers that cover huge areas of land near the poles, glaciers are responsible for breaking up rock and moving sediment as they move across the land. 

Below is a chart of average speed of movement of an alpine glacier per year, as well the amount of sediment displaced by the glacier. 

Two scientists have done research on an alpine lake that lies in the path of the glacier. Each took five samples of sediment from the lake.

Scientist 1 believes that the glacier is beginning to melt as it moves lower in elevation, releasing some of the sediment it has carried into mountain streams and springs, causing the makeup of sediments in the lake to change. He notes that the sediment from the lake bed contains brown chert, a rock that can only be found in elevations higher than that of the lake. Scientist 1 took his sample from the sediments that washed ashore on the beach of the lake.

Scientist 2 believes the glacier is not melting, but displacing rock beds so that the sediment loosens and breaks free of the bedrock and then is carried by wind and other erosive elements to the lake. He notes that the sediment from the lake bed contains only trace amounts of the brown chert, not enough to suggest the glacier is melting. Scientist 2 took his samples from sediment deposits at the bottom of the lake. 

Below is a chart of the sediment collection samples and the percentage of brown chert found in each.

What could have caused the difference in percentages of brown chert found in the sediment collected by each scientist?

A scientist has observed a new planet, Planet H. It was discovered that Planet H has water on its surface. As a result, it is being investigated to determine if it is possible for Planet H to sustain human life. Futhermore, observations revealed that Planet H has four moons: Moon J, Moon K, Moon L, and Moon M. Each moon's radius, distance to Planet H, and time to orbit Planet H have been recorded in the provided table. 

Before allowing humans to live on Planet H, what should scientists invesitigate further? 

In a specific region, a scientist recorded the rainfall, in inches, during the months of May, June, July and August. The scientist recorded this data in the same spot each month over four years. The purpose of this study was to see how the new factories built in the area impacted the rainfall in that location. 

What improvements can be made to this experiment? 

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. 

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

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? 

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? 

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.

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.

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