Unit 1 Study Guide Name:____________________________ Learning Target 1: I can explain how the sun, moon and planets were formed. 1. How long ago did the universe form? What was this event called? 2. How long after the formation of the universe was our sun created? 3. What are the two most common elements in the universe? 4. What are the planets of the solar system in order from the sun? Include the composition of the planets. 5. About how old is earth? 6. What are the four theories of lunar formation? Briefly explain them. 7. How are stars and planets formed? Learning Target 2: I can explain the internal structure of Earth and evidence we have to support it. 1. Name the three compositional and 5 mechanical layers of Earth and give couple facts about each that we have emphasized in class. 2. What does density have to do with the layers? 3. What is the major element that makes up the crust? How is that possible? 4. What are the major elements that make up the core? 5. What are the three sources of earth’s internal heat? Which one is the largest? 6. What are the major differences between the lithosphere and asthenosphere? 7. Why does Earth have a magnetic field and what makes it? Learning Target 3: I can explain and demonstrate the methods scientists have used to discover Earth’s history. 1. Explain relative age dating. 2. Explain correlation. 3. Explain radiometric dating. 4. Put the following strata in order. 5. What are the four principles of geology? Explain them. 6. What happens to the amount of parent and daughter isotopes in a sample as time goes on? 7. Why is it hard to come up with the geologic time scale? 8. Why is correlation necessary for putting together the geologic time scale? Learning Target 4: I can explain the structure of the Geologic time scale and identify important events in Earth’s history. 1. About how long has earth had life that was not microscopic? 2. Put the following in order from the first to appear on earth to the latest to appear. Reptiles Land plants Trilobites Bacteria Humans 3. About how much of earth’s history was spent with no life or microscopic life? 4. What type of event separates the Eras of earth’s history? 5. What are the units of the geologic time scale in order from largest to smallest?