Question 1

What is the most abundant element in the interstellar medium?

Accepted Answer

A)  carbon 
B)  iron dust 
C)  carbon dust 
D)  helium 
E)  hydrogen 
A)  carbon 
B)  iron dust 
C)  carbon dust 
D)  helium 
E)  hydrogen

Question 2

The interstellar medium is composed of mainly _____.

Accepted Answer

A)  equal parts of gas and dust 
B)  mostly dust and some gas 
C)  mostly gas and some dust 
D)  dust only 
E)  gas only 
A)  equal parts of gas and dust 
B)  mostly dust and some gas 
C)  mostly gas and some dust 
D)  dust only 
E)  gas only

Question 3

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

Accepted Answer

The dust in the ISM makes distant stars

Question 4

Briefly discuss the gas-stars-gas cycle.

Accepted Answer

During a star's lifetime, it fuses hydro

Question 5

Which type of nebula is produced when a star, hotter than 25,000 K, excites the gas near it to produce an emission spectrum producing a distinctive pink color?

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 6

The pressure of a gas depends on the ____ and ____ of the gas.

Accepted Answer

A)  density; volume 
B)  temperature; density 
C)  temperature; mass 
D)  temperature; volume 
E)  density; mass 
A)  density; volume 
B)  temperature; density 
C)  temperature; mass 
D)  temperature; volume 
E)  density; mass

Question 7

What observations demonstrate the existence of an interstellar medium?

Accepted Answer

1  We can see the three different types

Question 8

H II Regions are also called emission nebulae.

Accepted Answer

A) True 
 B)False

Question 9

To an observer on Earth, dust in the interstellar medium will cause a star to appear _______________ and_______________than it really is.

Accepted Answer

fainter; c

Question 10

The ground state of hydrogen has two closely-spaced energy levels, where oneelectron is spinning up and the other is spinning down. This energy transition corresponds to releasing excess energy as a photon at what wavelength?

Accepted Answer

A)  21 centimeters 
B)  21 millimeters 
C)  21 meters 
D)  22.2 centimeters 
E)  22.2 millimeters 
A)  21 centimeters 
B)  21 millimeters 
C)  21 meters 
D)  22.2 centimeters 
E)  22.2 millimeters

Question 11

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

Accepted Answer

The 21-cm radiation is another example o

What is the most abundant element in the interstellar medium?

The interstellar medium is composed of mainly _____.

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

Briefly discuss the gas-stars-gas cycle.

Which type of nebula is produced when a star, hotter than 25,000 K, excites the gas near it to produce an emission spectrum producing a distinctive pink color?

The pressure of a gas depends on the and of the gas.

What observations demonstrate the existence of an interstellar medium?

H II Regions are also called emission nebulae.

To an observer on Earth, dust in the interstellar medium will cause a star to appear _ and_than it really is.

The ground state of hydrogen has two closely-spaced energy levels, where oneelectron is spinning up and the other is spinning down. This energy transition corresponds to releasing excess energy as a photon at what wavelength?

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

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

Astrobiology

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

Exam 10: The Interstellar Medium

What is the most abundant element in the interstellar medium?

The interstellar medium is composed of mainly _____.

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

Briefly discuss the gas-stars-gas cycle.

Which type of nebula is produced when a star, hotter than 25,000 K, excites the gas near it to produce an emission spectrum producing a distinctive pink color?

The pressure of a gas depends on the ____ and ____ of the gas.

What observations demonstrate the existence of an interstellar medium?

H II Regions are also called emission nebulae.

To an observer on Earth, dust in the interstellar medium will cause a star to appear _______________ and_______________than it really is.

The ground state of hydrogen has two closely-spaced energy levels, where oneelectron is spinning up and the other is spinning down. This energy transition corresponds to releasing excess energy as a photon at what wavelength?

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

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

Astrobiology

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

The pressure of a gas depends on the and of the gas.

To an observer on Earth, dust in the interstellar medium will cause a star to appear _ and_than it really is.