Question 1

Distinguish between pressure and density .   How are they related to each other?

Accepted Answer

Pressure is a measure of the force that

Question 2

If hydrogen (H2) gas is the most common molecule found within the interstellar medium, then why do astronomers measure the amount of carbon monoxide (CO) gas to map molecular clouds?

Accepted Answer

Hydrogen (H₂ is the most common molecule

Question 3

The coronal gas in the interstellar medium has very high temperatures similar to the Sun's corona.

Accepted Answer

A) True 
 B)False

Question 4

Briefly discuss the gas-stars-gas cycle.

Accepted Answer

During a star's lifetime, it fuses hydro

Question 5

Describe three ways in which astronomers can distinguish between interstellar absorption lines and stellar absorption lines.

Accepted Answer

Some stellar spectra contain absorption

Question 6

H II Regions are also called emission nebulae.

Accepted Answer

A) True 
 B)False

Question 7

X-rays come from certain regions of the interstellar medium because gas molecules in those regions are at a very high density.

Accepted Answer

A) True 
 B)False

Question 8

Why is the sky blue during the day?

Accepted Answer

The sky appears blue during th

Question 9

What observations demonstrate the existence of an interstellar medium?

Accepted Answer

1.  We can see the three different types

Question 10

The _______________ is a high temperature, low density region in the interstellar medium around the Sun.

Accepted Answer

The answer of The _______________ is a high temperature, low...

Question 11

_______________ require that a young hot star (T ≥ 25,000 K) be relatively nearby.

Accepted Answer

The answer of _______________ require that a young hot star...

Question 12

What observations indicate the presence of dust in the interstellar medium?

Accepted Answer

The dust in the ISM makes distant stars

Question 13

Which type of nebulaeare twisted and distorted clouds of gas and dust dense enough to obstruct the view of the more distant stars?

Accepted Answer

A)  emission nebulae 
B)  H I 
C)  reflection nebulae 
D)  dark nebulae 
E)  spectral type B6 
A)  emission nebulae 
B)  H I 
C)  reflection nebulae 
D)  dark nebulae 
E)  spectral type B6

Question 14

The emission lines from O III are called ____ because they are not visible laboratories on Earth due to the much greater pressure of the gas on Earth.

Accepted Answer

A)  unique lines 
B)  unresolved lines 
C)  forbidden lines 
D)  unseen lines 
E)  "fathom" lines 
A)  unique lines 
B)  unresolved lines 
C)  forbidden lines 
D)  unseen lines 
E)  "fathom" lines

Question 15

Coronal gas radiates energy at ______________ wavelengths.

Accepted Answer

The answer of Coronal gas radiates energy at ______________ wavelengths....

Question 16

The intercloud medium is believed to make up 90 percent of the mass of the interstellar medium.

Accepted Answer

A) True 
 B)False

Question 17

List the three types of nebulae in the Interstellar Medium.

Accepted Answer

H II  regions (or em

Question 18

Why doesn't warm, dense hydrogen emit 21-cm radiation?

Accepted Answer

The 21-cm radiation is another example o

Question 19

What are "forbidden lines"? Briefly describe how they form.

Accepted Answer

Forbidden lines are certain lines in the

Question 20

Stars are born from the interstellar medium, and aging or dying stars return gas and dust back into the interstellar medium.

Accepted Answer

A) True 
 B)False

Exam 10: The Interstellar Medium

Distinguish between pressure and density . How are they related to each other?

If hydrogen (H2) gas is the most common molecule found within the interstellar medium, then why do astronomers measure the amount of carbon monoxide (CO) gas to map molecular clouds?

The coronal gas in the interstellar medium has very high temperatures similar to the Sun's corona.

Briefly discuss the gas-stars-gas cycle.

Describe three ways in which astronomers can distinguish between interstellar absorption lines and stellar absorption lines.

H II Regions are also called emission nebulae.

X-rays come from certain regions of the interstellar medium because gas molecules in those regions are at a very high density.

Why is the sky blue during the day?

What observations demonstrate the existence of an interstellar medium?

The _______________ is a high temperature, low density region in the interstellar medium around the Sun.

_______________ require that a young hot star (T ≥ 25,000 K) be relatively nearby.

What observations indicate the presence of dust in the interstellar medium?

Which type of nebulaeare twisted and distorted clouds of gas and dust dense enough to obstruct the view of the more distant stars?

The emission lines from O III are called ____ because they are not visible laboratories on Earth due to the much greater pressure of the gas on Earth.

Coronal gas radiates energy at ______________ wavelengths.

The intercloud medium is believed to make up 90 percent of the mass of the interstellar medium.

List the three types of nebulae in the Interstellar Medium.

Why doesn't warm, dense hydrogen emit 21-cm radiation?

What are "forbidden lines"? Briefly describe how they form.

Stars are born from the interstellar medium, and aging or dying stars return gas and dust back into the interstellar medium.

Here and Now

A Users Guide to the Sky

Moon Phases and Eclipses

Origins of Modern Astronomy

Gravity

Light and Telescopes

Atoms and Spectra

The Sun

The Family of Stars

Formation and Structure of Stars

Stellar Evolution

Deaths of Stars

Neutron Stars and Black Holes

The Milky Way Galaxy

Galaxies

Supermassive Black Holes and Active Galaxies

Modern Cosmology

Origin of the Solar System and Extrasolar Planets

Earth the Active Planet

The Moon and Mercury

Venus and Mars

Jupiter and Saturn

Uranus Neptune Pluto and the Kuiper Belt

Meteorites Asteroids and Comets

Astrobiology

Filters

If hydrogen (H₂) gas is the most common molecule found within the interstellar medium, then why do astronomers measure the amount of carbon monoxide (CO) gas to map molecular clouds?