Question 1

HI clouds can be observed using 21-cm radiation.

Accepted Answer

A) True 
 B)False  True

Question 2

Which of the following is not evidence of the existence of an interstellar medium?

Accepted Answer

A)  extinction 
B)  narrow calcium lines in the spectra of O and B stars 
C)  reddening 
D)  dark clouds 
E)  molecular bands in the spectra of cool stars 
A)  extinction 
B)  narrow calcium lines in the spectra of O and B stars 
C)  reddening 
D)  dark clouds 
E)  molecular bands in the spectra of cool stars E

Question 3

The presence of forbidden lines in the spectra of emission nebula indicates that the

Accepted Answer

A)  nebula has a very high temperature. 
B)  nebula contains large amounts of hydrogen. 
C)  gas in the nebula has a very low density. 
D)  dust in the nebula is composed of very small grains of silicates and carbon. 
E)  nebula is very near a star whose temperature is less than that of the sun. 
A)  nebula has a very high temperature. 
B)  nebula contains large amounts of hydrogen. 
C)  gas in the nebula has a very low density. 
D)  dust in the nebula is composed of very small grains of silicates and carbon. 
E)  nebula is very near a star whose temperature is less than that of the sun. C

Question 4

Bok globules are small,dark fragments of the interstellar medium.

Accepted Answer

A) True 
 B)False

Question 5

Which of the following properties are not associated with HII regions?

Accepted Answer

A)  High temperature 
B)  High density 
C)  Bright nebulae 
D)  Ionized gas 
A)  High temperature 
B)  High density 
C)  Bright nebulae 
D)  Ionized gas

Question 6

HII regions are found near stars cooler than 25,000 K because large amounts of ultraviolet photons would destroy the hydrogen atoms in the gas.

Accepted Answer

A) True 
 B)False

Question 7

____________________ are cool,with temperatures of 50 to 150 K and densities of ten to a few hundreds of atoms per cubic centimeter.

Accepted Answer

The answer of ____________________ are cool,with temperatures of 50 to...

Question 8

____ is(are)believed to make up 50 percent of the mass of the interstellar medium.

Accepted Answer

A)  The intercloud medium 
B)  HI clouds 
C)  Coronal gas 
D)  Molecular clouds 
E)  Dark nebulae 
A)  The intercloud medium 
B)  HI clouds 
C)  Coronal gas 
D)  Molecular clouds 
E)  Dark nebulae

Question 9

HII emission nebula regions are found around _________________.

Accepted Answer

A)  high temperature stars 
B)  very cool stars 
C)  solitary planets 
D)  Wrong.Interstellar hydrogen only exists in non-ionized HI form. 
A)  high temperature stars 
B)  very cool stars 
C)  solitary planets 
D)  Wrong.Interstellar hydrogen only exists in non-ionized HI form.

Question 10

Absorption lines due to interstellar gas

Accepted Answer

A)  are wider than the lines from stars because the gas is hotter than most stars. 
B)  are more narrow than the lines from stars because the gas has a lower pressure than stars. 
C)  indicate that the interstellar medium contains dust. 
D)  indicate that the interstellar medium is expanding away from the sun. 
E)  none of the above 
A)  are wider than the lines from stars because the gas is hotter than most stars. 
B)  are more narrow than the lines from stars because the gas has a lower pressure than stars. 
C)  indicate that the interstellar medium contains dust. 
D)  indicate that the interstellar medium is expanding away from the sun. 
E)  none of the above

Question 11

Stars are born in

Accepted Answer

A)  reflection nebulae. 
B)  dense molecular clouds. 
C)  HII regions. 
D)  the intercloud medium. 
E)  the local bubble. 
A)  reflection nebulae. 
B)  dense molecular clouds. 
C)  HII regions. 
D)  the intercloud medium. 
E)  the local bubble.

Question 12

The extinction of starlight due to the interstellar medium

Accepted Answer

A)  I & III 
B)  II & III 
C)  I & IV 
D)  II & IV 
E)  only IV 
A)  I & III 
B)  II & III 
C)  I & IV 
D)  II & IV 
E)  only IV

Question 13

Molecular clouds can be observed

Accepted Answer

A)  using infrared telescopes to detect ionized gas in the clouds. 
B)  using x-ray telescope to observe the x-ray radiation from the molecules in the cloud. 
C)  using radio telescopes to observe the CO emission from the clouds. 
D)  by looking for blue wispy regions near star clusters. 
E)  by looking for the 21-cm radiation from hydrogen. 
A)  using infrared telescopes to detect ionized gas in the clouds. 
B)  using x-ray telescope to observe the x-ray radiation from the molecules in the cloud. 
C)  using radio telescopes to observe the CO emission from the clouds. 
D)  by looking for blue wispy regions near star clusters. 
E)  by looking for the 21-cm radiation from hydrogen.

Question 14

Coronal gas radiates energy at

Accepted Answer

A)  gamma-ray wavelengths. 
B)  x-ray wavelengths. 
C)  visible wavelengths. 
D)  infrared wavelengths. 
E)  radio wavelengths. 
A)  gamma-ray wavelengths. 
B)  x-ray wavelengths. 
C)  visible wavelengths. 
D)  infrared wavelengths. 
E)  radio wavelengths.

Question 15

The intercloud medium has the highest density of the components of the interstellar medium.

Accepted Answer

A) True 
 B)False

Question 16

Absorption lines produced by the interstellar medium indicate that some components of the interstellar medium are cold and of a very low density because

Accepted Answer

A)  the lines are blue shifted. 
B)  the lines are red shifted. 
C)  the lines are extremely broad. 
D)  the lines are extremely narrow. 
E)  the lines are much darker than the stellar lines. 
A)  the lines are blue shifted. 
B)  the lines are red shifted. 
C)  the lines are extremely broad. 
D)  the lines are extremely narrow. 
E)  the lines are much darker than the stellar lines.

Question 17

____ is(are)believed to be produced by supernova explosions.

Accepted Answer

A)  Coronal gas 
B)  HI clouds 
C)  Molecular clouds 
D)  Reflection nebulae 
E)  Dark nebulae 
A)  Coronal gas 
B)  HI clouds 
C)  Molecular clouds 
D)  Reflection nebulae 
E)  Dark nebulae

Question 18

The air inside two balloons has the same temperature,but balloon A has a twice the pressure of balloon B.What does this tell us about the density of the air inside the two balloons?

Accepted Answer

A)  The air in balloons A and B have the same density. 
B)  The air in balloon B is more dense than the air in balloon A. 
C)  The air in balloon A is more dense than the air in balloon B. 
A)  The air in balloons A and B have the same density. 
B)  The air in balloon B is more dense than the air in balloon A. 
C)  The air in balloon A is more dense than the air in balloon B.

Question 19

Reflection nebulae look blue because they are reflecting light from a very hot source.

Accepted Answer

A) True 
 B)False

Question 20

The ____________________ is the component of the interstellar medium that is highly ionized and produces X-rays.

Accepted Answer

The answer of The ____________________ is the component of the...

Exam 10: The Interstellar Medium

HI clouds can be observed using 21-cm radiation.

Which of the following is not evidence of the existence of an interstellar medium?

The presence of forbidden lines in the spectra of emission nebula indicates that the

Bok globules are small,dark fragments of the interstellar medium.

Which of the following properties are not associated with HII regions?

HII regions are found near stars cooler than 25,000 K because large amounts of ultraviolet photons would destroy the hydrogen atoms in the gas.

____________________ are cool,with temperatures of 50 to 150 K and densities of ten to a few hundreds of atoms per cubic centimeter.

____ is(are)believed to make up 50 percent of the mass of the interstellar medium.

HII emission nebula regions are found around _________________.

Absorption lines due to interstellar gas

Stars are born in

The extinction of starlight due to the interstellar medium

Molecular clouds can be observed

Coronal gas radiates energy at

The intercloud medium has the highest density of the components of the interstellar medium.

Absorption lines produced by the interstellar medium indicate that some components of the interstellar medium are cold and of a very low density because

____ is(are)believed to be produced by supernova explosions.

The air inside two balloons has the same temperature,but balloon A has a twice the pressure of balloon B.What does this tell us about the density of the air inside the two balloons?

Reflection nebulae look blue because they are reflecting light from a very hot source.

The ____________________ is the component of the interstellar medium that is highly ionized and produces X-rays.

Here and Now

A Users Guide to the Sky

Cycles of the Moon

The Origin of Modern Astronomy

Gravity

Light and Telescopes

Atoms and Spectra

The Sun

The Family of Stars

The Formation and Structure of Stars

Stellar Evolution

The Deaths of Stars

Neutron Stars and Black Holes

The Milky Way Galaxy

Galaxies

Active Galaxies and Supermassive Black Holes

Modern Cosmology

The Origin of the Solar System

Earth: the Standard of Comparative Planetology

The Moon and Mercury: Comparing Airless Worlds

Venus and Mars

Jupiter and Saturn

Uranus,neptune,and the Kuiper Belt

Meteorites,asteroids,and Comets

Astrobiology: Life on Other Worlds

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