Question 1

When great currents of hot material rise inside the Sun (and cooler material sinks downward), energy is being transferred by a process known as:

Accepted Answer

A)  convection 
B)  radiation 
C)  conduction 
D)  equilibrium 
E)  politics 
A)  convection 
B)  radiation 
C)  conduction 
D)  equilibrium 
E)  politics A

Question 2

When two light elements collide to undergo nuclear fusion,

Accepted Answer

A)  the total mass involved increases 
B)  the positive charges in the nuclei attract, pulling the nuclei together faster and faster 
C)  some of the energy in their mass is released 
D)  only one survives; the other turns into a release of pure energy 
E)  the result is always to make nuclei of iron 
A)  the total mass involved increases 
B)  the positive charges in the nuclei attract, pulling the nuclei together faster and faster 
C)  some of the energy in their mass is released 
D)  only one survives; the other turns into a release of pure energy 
E)  the result is always to make nuclei of iron C

Question 3

Who pays the bill for the energy generated by nuclear fusion in the Sun? In other words, where does the energy pouring out of the Sun come from ultimately?

Accepted Answer

A)  the Sun is spinning more slowly as time goes on; rotation energy is lost 
B)  heavy nuclei are breaking apart into lighter nuclei 
C)  a little bit of mass is lost in each fusion reaction and is turned into energy (the Sun is losing mass) 
D)  material (like meteorites) is falling into the Sun and being vaporized to produce energy 
E)  American taxpayers pay this bill, as they do so many others! 
A)  the Sun is spinning more slowly as time goes on; rotation energy is lost 
B)  heavy nuclei are breaking apart into lighter nuclei 
C)  a little bit of mass is lost in each fusion reaction and is turned into energy (the Sun is losing mass) 
D)  material (like meteorites) is falling into the Sun and being vaporized to produce energy 
E)  American taxpayers pay this bill, as they do so many others! C

Question 4

The process of fusion that keeps our Sun shining begins with which building blocks?

Accepted Answer

A)  two electrons 
B)  two deuterons 
C)  two protons 
D)  two Einsteinium nuclei 
E)  two neutrinos 
A)  two electrons 
B)  two deuterons 
C)  two protons 
D)  two Einsteinium nuclei 
E)  two neutrinos

Question 5

A friend (who does not have the new awareness which you have gained from this course) suggests that the mechanism that keeps the Sun shining as brightly as it does is the burning of coal. You brilliantly challenge his theory! Your challenge comes in several related steps; which of the following is one of those steps?

Accepted Answer

A)  we have found many more neutrinos than we expected in our underground experiments 
B)  new protostars shine by gravitational collapse (the heat of clumping) 
C)  the dating of radioactive rocks show that the Earth and thus the Sun are billions of years old 
D)  most of the Sun is made of antimatter (which explodes when it touches matter) 
E)  the C-N-O cycle can also produce helium 
A)  we have found many more neutrinos than we expected in our underground experiments 
B)  new protostars shine by gravitational collapse (the heat of clumping) 
C)  the dating of radioactive rocks show that the Earth and thus the Sun are billions of years old 
D)  most of the Sun is made of antimatter (which explodes when it touches matter) 
E)  the C-N-O cycle can also produce helium

Question 6

Which of the following is a way for astronomers to learn more about the interior of the Sun?

Accepted Answer

A)  study the corona during eclipses of the Sun 
B)  study the oscillations (pulsations) of the Sun's surface 
C)  follow the orbit of Mercury, the closest planet to the Sun 
D)  take photographs of the Sun in the light absorbed by hydrogen atoms 
E)  study the accounts in ancient legends of the realm where the devil is supposed to live 
A)  study the corona during eclipses of the Sun 
B)  study the oscillations (pulsations) of the Sun's surface 
C)  follow the orbit of Mercury, the closest planet to the Sun 
D)  take photographs of the Sun in the light absorbed by hydrogen atoms 
E)  study the accounts in ancient legends of the realm where the devil is supposed to live

Question 7

When did scientist begin to understand how the Sun produces all the energy that it does?

Accepted Answer

A)  Most of the process was already understood by the ancient Greeks 
B)  Most of the process was understood by the end of the 18th century (the year 1800) 
C)  Most of the process was understood by the end of the 19th century (the year 1900) 
D)  The process was not well understood until the 1930's 
E)  You can't fool me; astronomers still don't have a clue about how the Sun produces energy 
A)  Most of the process was already understood by the ancient Greeks 
B)  Most of the process was understood by the end of the 18th century (the year 1800) 
C)  Most of the process was understood by the end of the 19th century (the year 1900) 
D)  The process was not well understood until the 1930's 
E)  You can't fool me; astronomers still don't have a clue about how the Sun produces energy

Question 8

The strongest force we know is

Accepted Answer

A)  gravity, which holds the Earth and the Sun together 
B)  electricity, which pulls unlike charges together 
C)  the nuclear force which holds nuclei together 
D)  the attraction of Bayonne, New Jersey, for tourists 
E)  none of the above 
A)  gravity, which holds the Earth and the Sun together 
B)  electricity, which pulls unlike charges together 
C)  the nuclear force which holds nuclei together 
D)  the attraction of Bayonne, New Jersey, for tourists 
E)  none of the above

Question 9

According to the formula E=mc2,

Accepted Answer

A)  mass has to travel at the speed of light before it can produce any energy 
B)  energy can travel much faster than light (in fact its speed can be the speed of light squared) 
C)  a little bit of mass can be converted into a substantial amount of energy 
D)  when two masses collide, we always get a lot of light 
E)  Einstein was a male chauvinist twice over 
A)  mass has to travel at the speed of light before it can produce any energy 
B)  energy can travel much faster than light (in fact its speed can be the speed of light squared) 
C)  a little bit of mass can be converted into a substantial amount of energy 
D)  when two masses collide, we always get a lot of light 
E)  Einstein was a male chauvinist twice over

Question 10

At the end of the p-p chain of nuclear fusion in the Sun, hydrogen nuclei have been converted into:

Accepted Answer

A)  carbon nuclei 
B)  heavy hydrogen nuclei 
C)  antimatter and nothing else 
D)  a helium nucleus 
E)  a lithium nucleus 
A)  carbon nuclei 
B)  heavy hydrogen nuclei 
C)  antimatter and nothing else 
D)  a helium nucleus 
E)  a lithium nucleus

Question 11

The material inside the Sun is in the form of a

Accepted Answer

A)  solid 
B)  liquid 
C)  plasma 
D)  ball of iron atoms 
E)  none of the above 
A)  solid 
B)  liquid 
C)  plasma 
D)  ball of iron atoms 
E)  none of the above

Question 12

Which of the following particles has the lowest mass?

Accepted Answer

A)  a neutrino 
B)  a proton 
C)  a neutron 
D)  an electron 
E)  the nucleus of a hydrogen atom 
A)  a neutrino 
B)  a proton 
C)  a neutron 
D)  an electron 
E)  the nucleus of a hydrogen atom

Question 13

In the formula E=mc2, the letter c stands for

Accepted Answer

A)  the speed of sound 
B)  the speed of an electron around the nucleus 
C)  the amount of energy contained in one hydrogen nucleus 
D)  the energy of a neutrino emerging from the Sun 
E)  the speed of light 
A)  the speed of sound 
B)  the speed of an electron around the nucleus 
C)  the amount of energy contained in one hydrogen nucleus 
D)  the energy of a neutrino emerging from the Sun 
E)  the speed of light

Question 14

Physicists Kelvin and Helmholtz in the last century proposed that the source of the Sun's energy could be:

Accepted Answer

A)  radioactive rocks 
B)  a slow contraction 
C)  meteorites falling in 
D)  the annihilation of antimatter 
E)  nuclear fusion
Section 16.2: Mass, Energy, and the Theory of Relativity 
A)  radioactive rocks 
B)  a slow contraction 
C)  meteorites falling in 
D)  the annihilation of antimatter 
E)  nuclear fusion
Section 16.2: Mass, Energy, and the Theory of Relativity

Question 15

When a large nucleus breaks apart (or is broken apart) into two smaller pieces, this is called

Accepted Answer

A)  nuclear fusion 
B)  nuclear binding 
C)  the p-p chain 
D)  equilibrium breaking 
E)  nuclear fission 
A)  nuclear fusion 
B)  nuclear binding 
C)  the p-p chain 
D)  equilibrium breaking 
E)  nuclear fission

Question 16

Which of the following statements about helioseismology experiments is FALSE:

Accepted Answer

A)  the pulsations these experiments measure take about an hour to emerge from the Sun's interior 
B)  small changes in the velocity of the waves of pulsation coming from inside the Sun help astronomers figure out the structure of the Sun's interior 
C)  helioseismology measures waves that are set up by the motion of neutrinos from the core of the Sun 
D)  a typical pulsation takes about 5 minutes to complete a full cycle from maximum to minimum speed and back again 
E)  Helioseismology allows astronomers to look under a sunspot and see how it works 
A)  the pulsations these experiments measure take about an hour to emerge from the Sun's interior 
B)  small changes in the velocity of the waves of pulsation coming from inside the Sun help astronomers figure out the structure of the Sun's interior 
C)  helioseismology measures waves that are set up by the motion of neutrinos from the core of the Sun 
D)  a typical pulsation takes about 5 minutes to complete a full cycle from maximum to minimum speed and back again 
E)  Helioseismology allows astronomers to look under a sunspot and see how it works

Question 17

Today we realize that the source of energy for the Sun is a process called

Accepted Answer

A)  nuclear fusion 
B)  Kelvin-Helmholtz contraction 
C)  mechanical to thermal energy conversion 
D)  radioactivity 
E)  dilithium crystal moderation 
A)  nuclear fusion 
B)  Kelvin-Helmholtz contraction 
C)  mechanical to thermal energy conversion 
D)  radioactivity 
E)  dilithium crystal moderation

Question 18

If it takes an average of 14 billion years before any proton inside the Sun will undergo fusion, and the Sun is only about 5 billion years old, why do astronomers believe that fusion is going on there now?

Accepted Answer

A)  fusion begins with particles even lighter than protons, which fuse more easily 
B)  there are an enormous number of protons inside the Sun, and some of them will fuse much sooner than the average 
C)  much more fusion takes place in the hot atmosphere of the Sun (where it can happen faster), not deep inside (where fusion is slow) 
D)  most of the fusion inside the Sun involves carbon, not protons; carbon fuses much more quickly 
E)  there is no fusion going on inside the Sun, and the fact given in the question is one of the reasons why 
A)  fusion begins with particles even lighter than protons, which fuse more easily 
B)  there are an enormous number of protons inside the Sun, and some of them will fuse much sooner than the average 
C)  much more fusion takes place in the hot atmosphere of the Sun (where it can happen faster), not deep inside (where fusion is slow) 
D)  most of the fusion inside the Sun involves carbon, not protons; carbon fuses much more quickly 
E)  there is no fusion going on inside the Sun, and the fact given in the question is one of the reasons why

Question 19

In the Sun, when a positron and an electron collide, they will produce:

Accepted Answer

A)  a deuteron 
B)  a neutron 
C)  hydrogen 
D)  a Neutron 
E)  energy in the form of a gamma ray 
A)  a deuteron 
B)  a neutron 
C)  hydrogen 
D)  a Neutron 
E)  energy in the form of a gamma ray

Question 20

Which of the following is NOT a product of the first step in the p-p chain of nuclear fusion?

Accepted Answer

A)  a form of hydrogen 
B)  a positron 
C)  a neutrino 
D)  a deuteron 
E)  a form of helium 
A)  a form of hydrogen 
B)  a positron 
C)  a neutrino 
D)  a deuteron 
E)  a form of helium

Exam 16: The Sun: a Nuclear Powerhouse

When great currents of hot material rise inside the Sun (and cooler material sinks downward), energy is being transferred by a process known as:

When two light elements collide to undergo nuclear fusion,

Who pays the bill for the energy generated by nuclear fusion in the Sun? In other words, where does the energy pouring out of the Sun come from ultimately?

The process of fusion that keeps our Sun shining begins with which building blocks?

Which of the following is a way for astronomers to learn more about the interior of the Sun?

When did scientist begin to understand how the Sun produces all the energy that it does?

The strongest force we know is

According to the formula E=mc2,

At the end of the p-p chain of nuclear fusion in the Sun, hydrogen nuclei have been converted into:

The material inside the Sun is in the form of a

Which of the following particles has the lowest mass?

In the formula E=mc2, the letter c stands for

Physicists Kelvin and Helmholtz in the last century proposed that the source of the Sun's energy could be:

When a large nucleus breaks apart (or is broken apart) into two smaller pieces, this is called

Which of the following statements about helioseismology experiments is FALSE:

Today we realize that the source of energy for the Sun is a process called

If it takes an average of 14 billion years before any proton inside the Sun will undergo fusion, and the Sun is only about 5 billion years old, why do astronomers believe that fusion is going on there now?

In the Sun, when a positron and an electron collide, they will produce:

Which of the following is NOT a product of the first step in the p-p chain of nuclear fusion?

Science and the Universe: a Brief Tour

Observing the Sky: the Birth of Astronomy

Orbits and Gravity

Earth, Moon, and Sky

Radiation and Spectra

Astronomical Instruments

Other Worlds: an Introduction to the Solar System

Earth As a Planet

Cratered Worlds: the Moon and Mercury

Earthlike Planets: Venus and Mars

The Giant Planets

Rings, Moons, and Pluto

Comets and Asteroids: Debris of the Solar System

Cosmic Samples and the Origin of the Solar System

The Sun: a Garden-Variety Star

Analyzing Starlight

The Stars: a Celestial Census

Celestial Distances

Between the Stars

The Birth of Stars and the Discovery of Planets Outside the Solar System

Stars From Adolescence to Old Age

The Death of Stars

Black Holes and Curved Space-Time

The Milky Way Galaxy

Galaxies

Active Galaxies, Quasars, and Supermassive Black Holes

The Evolution and Distribution of Galaxies

The Big Bang

Life in the Universe

Filters

According to the formula E=mc²,

In the formula E=mc², the letter c stands for