(A) 10 sunspots (B) 35 sunspots (C) 100 sunspots (D) 150 sunspots
11. During which of these time periods was the solar activity the least?
(A) 1705 (B) 1815 (C) 1885 (D) 1925
12. What is the lighter-colored region around the dark center of a sunspot called?
(A) pixel (B) corona (C) penumbra (D) granicular
13. What part of the Sun is directly below the photosphere?
(A) radiation zone (B) core (C) chromosphere (D) convection zone
14. What satellite above the Sun is gathering sun data?
(A) Hubble (B) Magellan (C) Yohkoh (D) Mariner
15. What is the average salinity of the Earth's ocean?
(A) 35 ppt (B) 2 ppt (C) 125 ppt (D) 900 ppt
16. The Alvin submersible is used to explore the depths of the ocean. Just how deep are trenches in the ocean?
(A) 10 feet (B) 10 miles (C) 4 miles (D) 26 miles
17. There are volcanoes on Earth. Are there volcanoes on other bodies (planets or moons) in the solar system?
(A) Yes (B) No
18. How many layers does the Earth's atmosphere have?
(A) 2 (B) None (C) 15 (D) Five