Study Guide for Rocks a Type of rocks c b a. Is the rock formed when molten rock cools. b. Is the rock formed when particles are compacted and cemented. c. Is the rock formed existing rock is changed deep beneath Earth’s surface. What do the three major types of rocks have in common? How are they different? How are intrusive and extrusive rocks similar? Different? What are the 3 factors that make sedimentary rocks? What are the 2 forces that can change rocks into metamorphic rocks? List the 5 ways rocks are formed. What type of rock are the following samples: 1. 2. 3. 4. 5. 6.