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Astronomy 209 / ASTR 209 Assignments 1, 2 & 3
– Latest 2026/2027 Update | Practice Review
with Verified Questions & Answers | Grade A
Which of the following is NOT one of the fundamental particles that we find inside a regular
atom? (Asgmt. 2, Q. 2)
a) protons
b) neutrons
c) positron
d) electrons
e) all four of the above are found in most atoms
c) positron
In the Sun, when a positron & an electron collide, what will they produce? (Asgmt. 2, Q. 3)
- Energy in the form of a gamma ray
Which of the following is the strongest force? (Asgmt. 2, Q. 4)
a) gravity, which holds the Earth & Sun together
b) electricity, which pulls unlike charges together
c) the nuclear force which holds protons together
d) none of the above
c) the nuclear force which holds protons together
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? (Asgmt. 2, Q. 5)
- B/c there is an enormous amount of protons inside the Sun, & some of them will fuse much
sooner than the average
At the end of the p-p chain of nuclear fusion in the Sun, what have hydrogen nuclei have been
converted into? (Asgmt. 2, Q. 6)
- A helium nucleus
The Sun is an enormous ball of gas. Left to itself, a ball of so many atoms should collapse under
its own tremendous gravity. Why is our Sun not collapsing? (Asgmt. 2, Q. 7)
- Nuclear fusion in the core keeps the temperature and the pressure inside the Sun at a high
enough level so that gravity is balanced
When great currents of hot material rise inside the Sun (and cooler material sinks downward),
energy is being transferred by a process known as: (Asgmt. 2, Q. 8)
- Convection
, Which of the following, produced at the core of the Sun, will take the shortest time to emerge
from the Sun's photosphere (surface)? (Asgmt. 2, Q. 9)
a) a positron
b) a neutrino
c) an x-ray produced after radiation has interacted with matter in the core
d) a deuteron
e) a photon (wave) of gamma-rays
b) a neutrino
Which of the following is a way for astronomers to learn more about the interior of the Sun?
(Asgmt. 2, Q. 10)
a) study the oscillations (pulsations) of the Sun's surface
b) study the accounts in ancient legends of the realm where the devil is supposed to live
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 corona during eclipses of the Sun
a) study the oscillations (pulsations) of the Sun's surface
What do astronomers & physicists now believe is happening to the 'missing' neutrinos (the ones
that our underground mine experiments could not find) that emerge from the Sun? (Asgmt. 2, Q.
11)
- They are turning into different types of neutrinos in neutrino oscillation
When an astronomer talks about the luminosity of a star, what are they talking about? (Asgmt. 2,
Q. 12)
- How much energy the star gives off each second
Two stars have the exact same luminosity, but star Y is four times dimmer looking that star X.
This means that: (Asgmt. 2, Q. 13)
a) star Y is four times as far away as star X
b) star Y is 16 times as far away as star X
c) we can't figure out the relative distance of the two stars from the information given
d) star Y is twice as far away as star X
e) star Y is half as far away as star X
d) star Y is twice as far away as star X
Which of the following looks the brightest in the sky? (Asgmt. 2, Q. 14)
a) a star with magnitude 10
b) a star with magnitude 1
c) a star with magnitude 6
d) a star with magnitude -1
e) you can't fool me, they all have the same brightness
d) a star with magnitude -1
Why are astronomers much more interested in the luminosity of a star than its' apparent
brightness? (Asgmt. 2, Q. 15)
- Because the luminosity tells us how bright a star really is
Astronomy 209 / ASTR 209 Assignments 1, 2 & 3
– Latest 2026/2027 Update | Practice Review
with Verified Questions & Answers | Grade A
Which of the following is NOT one of the fundamental particles that we find inside a regular
atom? (Asgmt. 2, Q. 2)
a) protons
b) neutrons
c) positron
d) electrons
e) all four of the above are found in most atoms
c) positron
In the Sun, when a positron & an electron collide, what will they produce? (Asgmt. 2, Q. 3)
- Energy in the form of a gamma ray
Which of the following is the strongest force? (Asgmt. 2, Q. 4)
a) gravity, which holds the Earth & Sun together
b) electricity, which pulls unlike charges together
c) the nuclear force which holds protons together
d) none of the above
c) the nuclear force which holds protons together
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? (Asgmt. 2, Q. 5)
- B/c there is an enormous amount of protons inside the Sun, & some of them will fuse much
sooner than the average
At the end of the p-p chain of nuclear fusion in the Sun, what have hydrogen nuclei have been
converted into? (Asgmt. 2, Q. 6)
- A helium nucleus
The Sun is an enormous ball of gas. Left to itself, a ball of so many atoms should collapse under
its own tremendous gravity. Why is our Sun not collapsing? (Asgmt. 2, Q. 7)
- Nuclear fusion in the core keeps the temperature and the pressure inside the Sun at a high
enough level so that gravity is balanced
When great currents of hot material rise inside the Sun (and cooler material sinks downward),
energy is being transferred by a process known as: (Asgmt. 2, Q. 8)
- Convection
, Which of the following, produced at the core of the Sun, will take the shortest time to emerge
from the Sun's photosphere (surface)? (Asgmt. 2, Q. 9)
a) a positron
b) a neutrino
c) an x-ray produced after radiation has interacted with matter in the core
d) a deuteron
e) a photon (wave) of gamma-rays
b) a neutrino
Which of the following is a way for astronomers to learn more about the interior of the Sun?
(Asgmt. 2, Q. 10)
a) study the oscillations (pulsations) of the Sun's surface
b) study the accounts in ancient legends of the realm where the devil is supposed to live
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 corona during eclipses of the Sun
a) study the oscillations (pulsations) of the Sun's surface
What do astronomers & physicists now believe is happening to the 'missing' neutrinos (the ones
that our underground mine experiments could not find) that emerge from the Sun? (Asgmt. 2, Q.
11)
- They are turning into different types of neutrinos in neutrino oscillation
When an astronomer talks about the luminosity of a star, what are they talking about? (Asgmt. 2,
Q. 12)
- How much energy the star gives off each second
Two stars have the exact same luminosity, but star Y is four times dimmer looking that star X.
This means that: (Asgmt. 2, Q. 13)
a) star Y is four times as far away as star X
b) star Y is 16 times as far away as star X
c) we can't figure out the relative distance of the two stars from the information given
d) star Y is twice as far away as star X
e) star Y is half as far away as star X
d) star Y is twice as far away as star X
Which of the following looks the brightest in the sky? (Asgmt. 2, Q. 14)
a) a star with magnitude 10
b) a star with magnitude 1
c) a star with magnitude 6
d) a star with magnitude -1
e) you can't fool me, they all have the same brightness
d) a star with magnitude -1
Why are astronomers much more interested in the luminosity of a star than its' apparent
brightness? (Asgmt. 2, Q. 15)
- Because the luminosity tells us how bright a star really is
