Question 1

Interstellar clouds are

Accepted Answer

A)  hydrogen gas,condensed out of the interstellar medium,like water clouds in the Earth's atmosphere. 
B)  regions where hydrogen tends to be denser than the surrounding gas. 
C)  regions where water condenses out of the interstellar medium. 
D)  oxygen gas,condensed out of the interstellar medium,like water clouds in the Earth's atmosphere. 
A)  hydrogen gas,condensed out of the interstellar medium,like water clouds in the Earth's atmosphere. 
B)  regions where hydrogen tends to be denser than the surrounding gas. 
C)  regions where water condenses out of the interstellar medium. 
D)  oxygen gas,condensed out of the interstellar medium,like water clouds in the Earth's atmosphere.

Question 2

The interstellar medium is divided up into three different kinds of gas clouds: cold gas at 10 K,warm gas at 8,000 K,and hot gas at about 1 million K.

Accepted Answer

A) True 
 B)False

Question 3

We detect neutral gas in the interstellar medium by looking for radiation at 21 cm that arises when

Accepted Answer

A)  an electron moves from the   to   state in a hydrogen atom. 
B)  an electron is ionized from a hydrogen atom. 
C)  carbon monoxide (CO)gas is excited by stellar radiation. 
D)  the spin of an electron flips and aligns with the spin of a proton in a hydrogen atom. 
A)  an electron moves from the   to   state in a hydrogen atom. 
B)  an electron is ionized from a hydrogen atom. 
C)  carbon monoxide (CO)gas is excited by stellar radiation. 
D)  the spin of an electron flips and aligns with the spin of a proton in a hydrogen atom.

Question 4

Why can't very bright protostars be seen in visible light?

Accepted Answer

They are cool,so they emit mos

Question 5

Compare the volume of the Sun with the volume of interstellar space it occupies.Is the occupied percentage large or small? (Note: the radius of the   ;the nearest star is 4.6 light-years away;

Accepted Answer

The volume of the Sun is given

Question 6

The H- ion is very important in protostars because it

Accepted Answer

A)  acts as a temperature regulator. 
B)  undergoes fusion and produces energy. 
C)  reacts with oxygen to produce water. 
D)  reduces angular momentum. 
A)  acts as a temperature regulator. 
B)  undergoes fusion and produces energy. 
C)  reacts with oxygen to produce water. 
D)  reduces angular momentum.

Question 7

The lowest-density gas in the interstellar medium is also the coldest.

Accepted Answer

A) True 
 B)False

Interstellar clouds are

The interstellar medium is divided up into three different kinds of gas clouds: cold gas at 10 K,warm gas at 8,000 K,and hot gas at about 1 million K.

We detect neutral gas in the interstellar medium by looking for radiation at 21 cm that arises when

Why can't very bright protostars be seen in visible light?

Compare the volume of the Sun with the volume of interstellar space it occupies.Is the occupied percentage large or small? (Note: the radius of the ;the nearest star is 4.6 light-years away;

The H^- ion is very important in protostars because it

The lowest-density gas in the interstellar medium is also the coldest.

Why Learn Astronomy

Patterns in the Skymotions of Earth

Gravity and Orbitsa Celestial Ballet

Light

The Tools of the Astronomer

The Birth and Evolution of Planetary Systems

The Terrestrial Planets and Earths Moon

Atmospheres of the Terrestrial Planets

Worlds of Gas and Liquidthe Giant Planets

Gravity Is More Than Keplers Laws

Planetary Adornmentsmoons and Rings

Dwarf Planets and Small Solar System Bodies

Taking the Measure of Stars

A Run-Of-The-Mill G-Type Starour Sun

Stars in the Slow Lanelow-Mass Stellar Evolution

Live Fast,die Younghigh-Mass Stellar Evolution

Our Expanding Universe

Galaxies

The Milky Waya Normal Spiral Galaxy

Modern Cosmology

The Origin of Structure

Life

Filters

Exam 15: Star Formation and the Interstellar Medium

Interstellar clouds are

The interstellar medium is divided up into three different kinds of gas clouds: cold gas at 10 K,warm gas at 8,000 K,and hot gas at about 1 million K.

We detect neutral gas in the interstellar medium by looking for radiation at 21 cm that arises when

Why can't very bright protostars be seen in visible light?

Compare the volume of the Sun with the volume of interstellar space it occupies.Is the occupied percentage large or small? (Note: the radius of the ;the nearest star is 4.6 light-years away;

The H- ion is very important in protostars because it

The lowest-density gas in the interstellar medium is also the coldest.

Why Learn Astronomy

Patterns in the Skymotions of Earth

Gravity and Orbitsa Celestial Ballet

Light

The Tools of the Astronomer

The Birth and Evolution of Planetary Systems

The Terrestrial Planets and Earths Moon

Atmospheres of the Terrestrial Planets

Worlds of Gas and Liquidthe Giant Planets

Gravity Is More Than Keplers Laws

Planetary Adornmentsmoons and Rings

Dwarf Planets and Small Solar System Bodies

Taking the Measure of Stars

A Run-Of-The-Mill G-Type Starour Sun

Stars in the Slow Lanelow-Mass Stellar Evolution

Live Fast,die Younghigh-Mass Stellar Evolution

Our Expanding Universe

Galaxies

The Milky Waya Normal Spiral Galaxy

Modern Cosmology

The Origin of Structure

Life

Filters

The H^- ion is very important in protostars because it