Download Name Date Life and Death of a Star 2015 1. In the main

Name ________________________
Date ________________
Life and Death of a Star 2015
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In the main-sequence, the core is slowly shrinking because
A. the mass of the star is slowly increasing
B. hydrogen fusing to helium makes the core more dense
C. carbon and iron are accumulating in the core
In a timeline that shows the sequence of events that occurs during the formation of a star, what happens after the
temperature increases in a proto-star?
A. nuclear fusion begins
B. gravity ceases to act
C. rotation begins
D. internal temperature drops
The heat can be radiated away from a protostar as long as it is
A. transparent
B. massive
C. opaque
D. small
Molecular clouds are a type of dark nebula.
A. TRUE
B. FALSE
The _____ of a star determines its temperature, luminosity, and diameter.
A. composition
B. mass
C. color
D. density
E. energy output
The more massive a main-sequence star, the faster it burns hydrogen. Therefore it's life is much shorter than averagesized stars.
A. TRUE
B. FLASE
Helium fusion is also known as
A. the triple alpha process
B. the carbon-12 process
C. the quadruple lindy process
D. the beryllium-8 process
The size of the supernova explosion is directly related to the mass of the star. In other words, the greater the mass, the
bigger the explosion.
A. TRUE
B. FALSE
Nuclear fusion begins when temperatures within a protostar reach about:
A. 300,000°C
B. 10,000,000°C
C. 30,000°C
D. 150,000,000°C
10. Some nebulae may be the remnant of a supernova explosion.
A. TRUE
B. FALSE
11. Prior to a supernova event, the heaviest element produced in the core of the most massive stars is
A. iron
B. neon
C. carbon
D. oxygen
E. helium
12. Immediately prior to a supernova explosion, core material collapses inward at speeds approaching
A. 37,500 km/sec
B. 100,000 km/sec
C. 1,000,000 km/sec
13. The picture below is of the
A. Eagle Nebula
B. Cocoon Nebula
C. Carina Nebula
14. Which correctly lists objects in order of decreasing mass?
A. Solar System, Jupiter, Sun, Earth
B. Sun, Solar System, Jupiter, Earth
C. Solar System, Sun, Jupiter, Earth
D. Solar System, Jupiter, Earth, Sun
15. At the precise moment of the supernova event, every element in the periodic table is formed and then ejected outward.
A. TRUE
B. FALSE
16. A star's core has contracted, meaning that density has increased and the atoms are closer together. If the atoms are
closer together, then their atomic collisions should:
A. Decrease
B. stay the same
C. Increase
17. The process of hydrogen fusion (proton-proton chain) releases neutrinos, positrons, and gamma rays as a by-product.
A. TRUE
B. FALSE
18. Molecular clouds are cold, only about
A. 10 K
B. 10,000,000 K
C. 10,000 K
D. 100 K
19. Molecular clouds form just about as many stars as Emission Nebulae and Reflection NEbulae.
A. TRUE
B. FALSE
20. A white-dwarf star may explode as a type 1a supernova if
A. if it enters a nebula
B. gets sucked into a black hole
C. enough hydrogen gas builds up on its surface
D. re-starts fusion in its core
21. All stars, including the Sun, have the following identical composition:
A. 25 percent helium; 73 percent hydrogen; and 2 percent oxygen
B. 25 percent helium; 73 percent hydrogen; and 2 percent other
C. 25 percent hydrogen; 73 percent helium; and 2 percent other
D. 25 percent hydrogen; 73 percent helium; and 2 percent oxygen
22. If the force of fusion in the star decreases, then gravity will now dominate hydrostatic equilibrium. This results in an
unstable star. What should happen next?
A. The core of the star will contract
B. the gas presure will puff off the outer layers ofthe star to form a nebula
C. the core of the star will explode
23. Pulsars have a strong magnetic field and rotate very rapidly.
A. TRUE
B. FALSE
24. The density of the interstellar medium makes it almost a complete vacuum.
A. TRUE
B. FALSE
25. If the solar mass is greater than 20, a star may collapse into a
A. white dwarf
B. magnetar
C. black hole
D. pulsar
26. The remnant gasses and dust of a supernova may eventually cool and become a
A. dark nebula
B. molecular cloud
C. a new star
D. a new solar system
E. all of the above
27. Many star systems in our galaxy are binary star systems.
A. TRUE
B. FALSE
28. The energy that triggers a supernova event comes FIRST from
A. fusion of elements heavier than iron
B. collision with another star
C. gravitational collapse of the core of a massive star
29. When helium fusion takes over in a star's core, what happens?
A. the energy output decreases
B. energy output stays the same
C. the energy output increases
30. A star that is gravitationally bound to another may be a
A. binary
B. red giant
C. white dwarf
D. constellation
31. A type II supernova occurs in stars 9 solar masses or greater.
A. TRUE
B. FALSE
32. Molecular Clouds are relatively cold compared to other nebula types.
A. TRUE
B. FALSE
33. Stars more massive than the Sun use up their fuel at a slower rate.
A. TRUE
B. FALSE
34. The state of matter found in the Sun’s interior is plasma.
A. TRUE
B. FALSE
35. One Dark Nebula can produce thousands of stars.
A. TRUE
B. FALSE
36. We know black holes exist because
A. they are predicted by the theory of relativity
B. gravitational lensing
C. their effects on nearby stars
D. all of the above
37. It takes four hydrogen nuclei to produce one helium-4 nucleus.
A. TRUE
B. FALSE
38. The sun is in which point of it's life cycle?
A. main-sequence
B. protostar
C. red dwarf
D. post-main-sequence
E. red giant
39. In the main sequence, as the core slowly contracts, the star gradually grows larger, brighter, and hotter. This is
because
A. more heat is generated in the core due to increased density
B. nuclear fusion is happening at a slightly faster rate
C. both of the above
D. neither of the above
40. Pulsars are classified according to
A. their size
B. how they generate energy
C. their brightness
41. A magnetar is a type of pulsar that generates energy by
A. an extremely strong magnetic field
B. rotation
C. gravitational contraction
42. Our sun will eventually become a supernova.
A. TRUE
B. FALSE
43. "High mass stars" eventually become SUPERGIANTS rather than simply red giants.
A. TRUE
B. FALSE
44. As the core of a main-sequence star depletes its supply of hydrogen, the core begins to
A. collapse
B. get hotter
C. start helium fusion
D. A and B
E. none of the above
45. Neutron stars are so dense that one teaspoon of its material will weigh as much as
A. the sun
B. Jupiter
C. a car
D. Earth
Life and Death of a Star 2015
1. hydrogen fusing to helium makes the core more dense
2. nuclear fusion begins
3. transparent
4. TRUE
5. mass
6. TRUE
7. the triple alpha process
8. TRUE
9. 10,000,000°C
10. TRUE
11. iron
12. 100,000 km/sec
13. Eagle Nebula
14. Solar System, Sun, Jupiter, Earth
15. TRUE
16. Increase
17. TRUE
18. 10 K
19. FALSE
20. enough hydrogen gas builds up on its surface
21. 25 percent helium; 73 percent hydrogen; and 2 percent other
22. The core of the star will contract
23. TRUE
24. TRUE
25. black hole
26. all of the above
27. TRUE
28. gravitational collapse of the core of a massive star
29. the energy output increases
30. binary
31. TRUE
32. TRUE
33. FALSE
34. TRUE
35. TRUE
36. all of the above
37. TRUE
38. main-sequence
39. both of the above
40. how they generate energy
41. an extremely strong magnetic field
42. FALSE
43. TRUE
44. A and B
45. Earth