Download Star Life Cycle Review 1. What is the first stage of star creation? A

Star Life Cycle Review
1.
What is the first stage of star creation?
A. Supernova
B. Nuclear fusion
C. expansion
D. protostar
2.
A Hertzsprung-Russell diagram helps to classify stars by color, temperature, size, and brightness (luminosity).
According to the diagram, an O-class main-sequence star is
A. the brightest of the main-sequence stars
B. the hottest of the main-sequence stars
C. the largest of the main-sequence stars
D. all of these
3.
Which of the following statements about stars is true?
A. The smaller a star is, the longer its life cycle.
B. The smaller a star is, the shorter its life cycle.
C. The larger a star is, the longer its life cycle.
D. All star's life cycles are about the same length, regardless of their size.
4.
A star's life cycle is similar to that of a living organism in which of the following ways?
A star fits into an ecological niche within its galaxy. Each star competes with other stars for a limited amount
A.
of resources.
B. A star requires a continual supply of material from other stars in order to survive for long periods of time.
C.
A star undergoes many different stages during its life. And after it dies, the material that made it up can be
used by future stars.
D. All stars were born when the universe began and will endure until the end of time.
5.
The table below describes the properties of several stars.
Star
Color
Temperature
Approximate
Radius
Betelgeuse
red
3,500 K
650000000 km
Sun
white-yellow
5,778 K
700000 km
Sirius A
blue
9,940 K
1200000 km
Pollux
orange
4,865 K
5500000 km
Which of the stars listed above is most likely considered a supergiant?
A. Sun
B. Pollux
C. Sirius A
D. Betelgeuse
6.
The mass of a star is many times bigger than the Sun. What other information is needed about the star in order to
estimate its age using the star life cycle?
A. its composition
B. its distance from Earth
C. its color
D. its location
Use the Hertzsprung-Russell diagram to answer the following question:
7.
Luminosity is measured in units of Solar luminosity. What is the spectral class of a main sequence star with a
luminosity equal to that of the Sun?
M
G
O
B
8.
The Sun is a medium-size star that, like other stars, is going through the star life cycle. Currently, the Sun is in the main
sequence stage of the cycle. What stage will the Sun likely enter next?
A. death
B. protostar
C. super red giant
D. red giant
9.
Which of the following is not something a star can turn into after it has run out of fuel?
A. white dwarf
B. brown dwarf
C. black hole
D. neutron star
10. How bright a star appears to be in the night sky depends on its actual brightness and its
A. mass.
B. temperature.
C. color.
D. distance from Earth.
11. An example of the Hertzsprung-Russell diagram is shown below. Using this diagram, what can you say about white
dwarfs? (Hint: Notice that the temperature on the x-axis is hotter on the left and cooler on the right.)
Source: www.nasa.gov
A. They are relatively dim, but very hot.
B. They are very bright, but relatively cool.
C. They are very bright and hot.
D. They are relatively dim and cool.
12. What are the two variables that are incorporated in the Hertzsprung-Russell diagram?
A. a star's luminosity (brightness) and its distance from earth
B. a star's age and its distance from earth
C. a star's age and its surface temperature
D. a star's luminosity (brightness) and its surface temperature
13. A star is born when gas and dust from a nebula become so dense and hot that nuclear fusion starts. Which of the
following forces is responsible for the formation of a star?
A. gravitation
B. magnetism
C. friction
D. electromagnetic energy
14. What is the name for the portion of a star's life cycle when it is using hydrogen for fuel?
A. white dwarf
B. red giant
C. main sequence
D. protostar
15. The color of a star is determined by its temperature, as the table below shows.
Color
Temperature (K)
blue
30,000-60,000
bluish
10,000-30,000
blue-white
7,500-10,000
white
6,000-7,500
yellow-white
5,000-6,000
orange
3,500-5,000
red
3,500 and less
What color are the coolest stars (based on temperature not on Mr. DelliGatti’s coolness )?
A. yellow
B. white
C. blue
D. red
16. Which of the following describes a major role of gravity in star formation?
The gravitational forces of planets push gases from their atmospheres to form a star at the solar system's
A.
center.
B.
Gravity causes an interstellar cloud fragment to expand rapidly until it is large enough to form a star at
its center.
C.
Asteroids passing by a solar system are pulled in by planets' gravities to form a star at the center of the
solar system.
D.
Gravity compresses gases at the center of a solar nebula until temperatures are high enough for
nuclear fusion to occur.