Download Intrusive and Extrusive Igneous Rocks Answer Key

Intrusive and Extrusive Igneous Rocks Answer Key 1) Igneous rocks only cool when magma reaches the surface of the Earth. a) true b) false 2) Igneous rocks cool very slowly on the surface of the Earth. a) true b) false 3) The size of crystals in an igneous rock is primarily determined by… a) the composition of the rock. b) how fast the rock forms. c) the elements in the rock. d) none of the above 4) A pluton in an igneous rock body that forms _within the crust_. 5) Granite… a) is the most common intrusive igneous rock. b) has very large crystals. c) is formed very slowly. d) all of the above e) a and b, but not c 6) Extrusive igneous rocks are also known as _volcanic_ rocks. 7) Extrusive igneous rocks _cool faster_ than intrusive igneous rocks. 8) Basalt… a) is the most common extrusive igneous rock. b) has very large crystals. c) makes up the ocean crust. d) all of the above e) a and c, but not b 9) The size of _the crystals_ in igneous rocks determine their texture. 10) _Extrusive_ igneous rocks are formed from lava.