DICTIONS: Choose and encircle the letter of your answer. 1. A volcano erupts in order to A. cool Earth's Interior C. Both A &B B. release pressure from Earth's interior D. None of the above 2. Which of the following is given off during a volcanic eruption? A. ash B. gases C. lava D. all of the above 3. What is the term for lava's resistance to flow? A. movement B. pressure C. silica D. viscosity 4. Which of the following statement is TRUE? A. The magma in a quiet eruption is low in silica. B. The magma in a quiet eruption is high in silica. C. The magma of an explosive eruption is low in silica. D. The silica content of magma has nothing to do with explosiveness. a volcanoes 5. Which characteristic of magma mainly determines its explosiveness? A. Amount B. Color C. Silica content D. temperature 6. Which of the following characteristics of a volcano depends on its magma emission? A. Age B. Location C. Shape D. Size 7. A thick layer of volcanic ash can be heavy enough to collapse the roofs of buildings because ash A. is solid C. becomes heavier as it cools B. cannot be blown by winds D. consists of tiny fragments of rocks that heavily piles up 8. Which of the following factors associated with huge volcanic eruptions may cause the decrease in the Earth's average temperature for a few years? A. Acid rain B. Heat C. Light D. Volcanic ash 9. Which is the most explosive type of eruption? A. Phreatic B. Plinian C. Strombolian D. Vulcanian 4 10. When lava reaches the surface of the Earth through volcanoes or through great fissures the rocks that are formed from the lava cooling and the hardening are called A. extrusive igneous rocks C. metamorphic B. intrusive igneous rocks D. sedimentary​