2. Match the most appropriate tool to the work:
_(a) Image processes in the hottest active regions of the Sun.
____ (b) Image corona outside solar eclipse.
_(c) Photograph the Sun's visible surface.
_(d) Image the Sun in the light of a particular element.
3. Define the astronomical unit (AU)._
(2) Optical solar telescope.
(3) Radio telescopes.
(5) Ultraviolet ray, X-ray, and gamma ray telescopes.
4. Sketch the Sun, and identify the corona, chromosphere, photosphere, convection zone, radiation zone, and core.
5. Estimate (a) diameter; (b) mass; and (c) surface temperature of the Sun.
6. Why is the sunspot cycle carefully monitored from Earth?
7. Identify the following phenomena of the Sun:
(a) Most energetic eruption of material from the solar corona.
(b) Bright cell that looks like rice grain in the photosphere.
(c) Dark, relatively cool blotches in the bright photosphere.
(d) Elementary particles predicted to be produced in nuclear reactions in the core.
(e) Tremendous, short-lived, explosive outburst of light and material.
(3) Coronal mass ejection.
(4) Solar neutrino.
8. What is the solar wind?_
9. List four ways that a flare and unusually big blasts of solar wind can affect
Earth's environment. (1)_
10. (a) What is the solar constant? (b) Why is it important to know if it is truly constant or if it varies with time?_
Compare your answers to the questions on the self-test with the answers given below. If all of your answers are correct, you are ready to go on to the next chapter. If you missed any questions, review the sections indicated in parentheses following the answer. If you missed several questions, you should probably reread the entire chapter carefully.
1. (1) The Sun is a free, nonpolluting, almost inexhaustible source of present and potential future energy.
(2) The Sun is the only star close enough to observe in detail, so astronomers use it to determine what other stars are like.
(3) Changes in the Sun's energy output affect Earth's climate, atmosphere, and weather, as well as power-transmission and communications systems. (Sections 4.1, 4.13)
2. (a) 5; (b) 1; (c) 2; (d) 4; (e) 3. (Section 4.7)
3. The astronomical unit (AU) is the average distance between the Earth and the Sun, about 150 million km (93 million miles) (officially 149,597,870 km). (Section 4.2)
4. See Figure 4.6, Regions of the Sun. (a) Corona; (b) chromosphere; (c) photosphere; (d) convection zone; (e) radiation zone; (f) core. (Section 4.4)
5. (a) 1,390,000 km (864,000 miles); (b) 2 x 1030 kg; (c) 5800 K (10,000° F). (Sections 4.2, 4.4, 4.6)
6. The sunspot cycle is watched carefully from Earth as an indicator of solar activity. The Sun is most active, with greatest outbursts of energy and radiation, during the years when sunspots are most numerous. It is least active in the years of sunspot minimums. (Sections 4.10, 4.13, 4.14)
7. (a) 3; (b) 2; (c) 5; (d) 4; (e) 1. (Sections 4.8, 4.9, 4.12, 4.14, 4.15)
8. A stream of energetic electrically charged particles that flows out from the Sun. (Section 4.14)
9. (1) Increased hazardous radiation; (2) auroras; (3) magnetic storms;
(4) atmospheric storms. (Sections 4.13, 4.14)
10. (a) The amount of the Sun's energy that falls per second on Earth's outer atmosphere, about 1400 watts per square meter (126 watts per square foot). (b) Changes in the solar constant might drastically change Earth's climate and atmosphere. (Sections 4.1, 4.13)
Was this article helpful?