Question

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air pressure - comprehension questions

1. read these sentences from the text.

\in the international space station, the density of the air is maintained so that it is similar to the density at the earths surface. therefore, the air pressure is the same in the space station as the earths surface (14.7 pounds per square inch).\
based on the text, what can you infer about the international space station?
a. heat or the number of molecules in the international space is greater than in the earths surface.
b. heat or the number of molecules in the international space is less than in the earths surface.
c. heat or a number of molecules was added or subtracted in the international space station.
d. there is no heat or molecule in the international space station.

1. what is the main idea of this text?

a. air pressure is the same in the international space station as in the earths surface because the density of air is maintained in the station.
b. air pressure in a container can be increased by adding molecules or heat, and it can be decreased by subtracting molecules or heat.
c. air pressure on earth decreases as elevation increases because the number of molecules decreases with height.
d. air pressure is observed by the exerted force of atoms and molecules, and it can be changed by adding or subtracting molecules or heat.

Explanation:

Question 4

To solve this, we analyze the relationship between air density, pressure, and factors like heat/molecules. The text says the space station’s air density (and thus pressure) is similar to Earth’s surface. Air pressure is related to heat and molecule number (more heat/molecules can increase pressure, less can decrease). Since the space station is a closed environment (unlike Earth’s open atmosphere), to maintain the same pressure as Earth’s surface, heat or molecules must have been adjusted (added or subtracted) to match Earth’s conditions.

• Option A: If heat/molecules were greater, pressure would likely be greater, but the text says pressure is the same, so A is wrong.
• Option B: If heat/molecules were less, pressure would likely be less, but pressure is the same, so B is wrong.
• Option C: Since the space station is a controlled environment, to match Earth’s pressure, heat or molecules must have been added or subtracted. This makes sense.
• Option D: The text states there is air (so molecules) and pressure, so D is wrong.

We need to identify the main idea of the text (about air pressure). Let's analyze each option:

• Option A: This focuses only on the space station example, but the main idea of a text about air pressure would likely be broader, not just about the space station.
• Option B: Talks about changing air pressure in a container by adding/subtracting molecules/heat. This is a fundamental concept about air pressure (how it can be manipulated), which is a core idea.
• Option C: Focuses on Earth’s air pressure with elevation, which is a specific aspect, not the main idea (unless the text is solely about that, but the given sentence is about the space station, suggesting the text is about air pressure in general, including how it’s changed).
• Option D: Describes what air pressure is and how it’s changed, but the wording is less clear than B about the methods (adding/subtracting molecules/heat to change pressure). Option B directly states how air pressure in a container (a general concept) can be increased/decreased, which is a key main idea about air pressure dynamics.

Answer:

C. Heat or a number of molecules was added or subtracted in the International Space Station.

Question 5