Download SELF-TEST: True or False? 1. The Sun is a rather

SELF-TEST: True or False?
1. The Sun is a rather normal star. HINT
2. The average density of the Sun is significantly greater than the density of the Earth. HINT
3. The Sun's diameter is about 10 times that of Earth. HINT
4. The Sun's differential rotation indicates that it is not solid. HINT
5. In the solar radiation zone, the gas is partly ionized. HINT
6. Convection involves cool gas rising to the solar surface, and hot gas sinking into the
interior. HINT
7. Absorption lines in the solar spectrum are produced mainly in the corona. HINT
8. There are as many absorption lines in the solar spectrum as there are elements present in the
Sun. HINT
9. The faintness of the chromosphere is a direct result of its low temperature. HINT
10. The temperature of the solar corona decreases with increasing radius. HINT
11. Sunspots are regions of intense magnetic fields. HINT
12. Prominences are large flames erupting from the burning surface of the Sun. HINT
13. Neutrinos are neutrons traveling close to the speed of light. HINT
SELF-TEST: Fill in the Blank
1. The part of the Sun we actually see is called the _____. HINT
2. Traveling outward from the surface, the two main regions of the solar atmosphere are the ____
and the _____. HINT
3. Below the solar surface, in order of increasing depth, lie the _____ zone, the _____ zone, and
the _____. HINT
4. The _____ seen on the surface of the Sun is evidence of convective cells. HINT
5. The Sun appears to have a well-defined edge because the thickness of the _____ is only 0.1
percent of the solar radius. HINT
6. _____ is the most abundant element in the Sun. HINT
7. _____ is the second most abundant element in the Sun. HINT
8. The two most abundant elements in the Sun make up about _____ percent of its
composition. HINT
9. The gas in the corona is highly _____. HINT
10. Sunspots appear dark because they are _____ than the surrounding gas of the
photosphere. HINT
11. The sunspot cycle is _____ years long; the solar cycle is _____ as long. HINT
12. The entire solar luminosity is produced in the _____ (give the region) of the Sun. HINT
13. The net result of the proton-proton chain is that ____ protons are fused into a nucleus of _____
, 2 _____ are emitted, and energy is released in the form of _____. HINT
14. The solar neutrino "problem" is the fact that astronomers observe too _____ neutrinos coming
from the Sun. HINT
REVIEW AND DISCUSSION
1. Name and briefly describe the main regions of the Sun. HINT
2. How massive is the Sun, compared with the Earth? HINT
3. How hot is the solar surface? The solar core? HINT
4. How do scientists construct models of the Sun? HINT
5. Describe how energy generated at the center of the Sun reaches Earth. HINT
6. Why does the Sun appear to have a sharp edge? HINT
7. Give the history of "coronium," and tell how it increased our understanding of the Sun. HINT
8. What is the solar wind? HINT
9. What is the cause of sunspots, flares, and prominences? HINT
10. What fuels the Sun's enormous energy output? HINT
11. What are the ingredients and the end result of the proton-proton chain in the Sun? Why is
energy released in the process? HINT
12. Why are scientists trying so hard to detect solar neutrinos? HINT
13. What would we observe on Earth if the Sun's internal energy source suddenly shut off? Would
the Sun darken instantaneously? If not, how long do you think it might take--minutes, days,
years, millions of years--for the Sun's light to begin to fade? Repeat the question for solar
neutrinos. HINT