NAME: ____________________________ Class: ______ Midterm Date: ________________ Midterm Study Guide: 6th grade Earth Science 1. In which direction do lines of latitude run? In which direction do lines of longitude run? Latitude: distance (in degrees) north or south of equator. Lines of latitude run West to East. It divides Earth in northern and southern hemispheres. Longitude: distance (in degrees) from prime meridian. Lines of Longitude run North to South. It divides Earth in western and eastern hemispheres. 2. Define geologic formation. It is a 3-D body of a certain kind of rock of a given age range 3. What is a fault contact? • Place where two rock formations are next to each other 4. Compare and contrast topographic map and geologic map. Topographic Maps: Use lines of equal elevation Refers to the shape of the surface. Identify natural features: mountains, valleys, rivers, lakes, coastlines Identify man-made features: buildings, roads, towns Geologic Maps: Represent geology of an area 5. Minerals are comprised of one or more __ELEMENTS__. 6. When would a mineral be classified as an ore? A mineral is an ore if it contains a useful substance that can be mined at a profit. 1 NAME: ____________________________ Class: ______ Midterm Date: ________________ 7. What is the softest mineral? What is the hardest mineral? Softest mineral: TALC Hardest mineral: Diamond 8. What are the characteristics of minerals? Naturally occurring Generally inorganic—can be organic Must be a solid Has a crystal structure Has a definite chemical composition 9. Define cleavage and fracture. – – 10. If a mineral breaks along a smooth, flat surface, it displays cleavage. If a mineral breaks along a rough, irregular surface, it displays fracture. How do you test for hardness? You can test the hardness of a mineral by observing how easily it is scratched. 11. What does the rock cycle show us? • • It shows the journey that a rock goes through. Forces on Earth’s surface and deep within the planets drive this cycle. • It can take thousands to millions of years for rocks to go through the rock cycle. 2 NAME: ____________________________ Class: ______ Midterm Date: ________________ 12. How do igneous rock form? Igneous rocks are formed from magma. As the temperature of magma decreases, crystals of minerals begin to form. Lava is magma on the surface of the Earth. 13. Define magma Magma is molten rock underneath Earth’s surface. 14. Define lava Lava is magma on the surface of the Earth. 15. • • • • Formed when rocks break down into smaller pieces or dissolve in water Formed by water, ice, wind, and gravity Often layered in nature Weight of the material above creates the cemented layers 16. • How do sedimentary rock form? Define rock. Is a natural solid mixture of particles 17. Changes that take place in rock never create or destroy _MATTER__. 18. What are the layers of earth? Define each one. What is each one made of? Crust: Is the thin, rocky outer layer of Earth Mantle: Lies below the crust and is the thick middle layer of Earth’s interior. Made of peridotite, is brittle, and contains a lot of oxygen, silicon, magnesium and iron. Mantle rock is denser than the crust. 3 NAME: ____________________________ Class: ______ Midterm Date: ________________ Lithosphere: Is the brittle, outer layer of Earth formed by the crust and uppermost mantle Outer Core: Outer layer is molten metal due to extremely high temperature Inner Core: Inner layer is solid due to extremely high pressure. 19. What is the thinnest layer of earth? The crust is thinnest layer of Earth. 20. What is the thickest layer of earth? The mantle is thickest layer of Earth. 21. Energy occurs in _MANY__ forms. 22. Define potential energy. Energy an object has when it is not moving (stored energy). 23. 24. Define kinetic energy. Kinetic energy – energy an object has because it is moving What are the three types of potential energy? Define each one. a) gravitational potential energy Due to downward pull of Earth’s gravity. The amount of gravitational potential energy depends on: – An object’s mass – An object’s height above the ground b) elastic potential energy: Is energy stored when an object is squeezed or stretched c) chemical potential energy: Energy stored in bonds between the atoms that make up matter 4 NAME: ____________________________ Class: ______ Midterm Date: ________________ 25. 26. What is heat? Heat is the transfer of thermal energy from a hot object to a cooler object From where to where does heat move in? Energy transfers from a hot object to a cooler object 27. What is a conductor? Give 2-3 examples. Conductors are materials in which thermal energy moves quickly. Examples: silver, copper, aluminum. 28. What is an insulator? Give 2-3 examples. Insulators are materials in which thermal energy moves slowly. Examples: wood, air. 29. What is temperature? What does it measure? o Temperature is a measure of heat. o Temperature is Measure of the average kinetic energy of the particles in a material. 30. How does a liquid thermometer work? What happens to the liquid inside? Thermometers contains red liquid inside a thin glass tube When the temperature of liquid increases, it expands, and volume increases. So, the height of a liquid in the tube increases When the temperature of liquid decreases, the liquid shrinks, so the height of liquid goes down The numbers on the side of thermometer shows the temp. 31. Define radiation. Transfer of thermal energy by electromagnetic waves Thermal energy can be transferred by radiation within matter and through space. Is the process that transfers energy from the Sun to Earth. 5 NAME: ____________________________ Class: ______ Midterm Date: ________________ 32. Define convection. Convection this is the transfer of thermal energy from one place to another. The particles must be able to move from place to place, so it only happens in liquids and gases. Convection happens because of differences in density in a fluid DENSITY: the amount of matter, or mass, contained in a unit volume of a material 33. Define conduction. Conduction is the transfer of thermal energy by collisions between particles in matter. 34. What is friction? Give an example. The resistance that one surface or object encounters when moving over another. Example: rubbing your hands together. 35. Define Lithosphere. Lithosphere: Is the brittle, outer layer of Earth formed by the crust and uppermost mantle 36. Who was Alfred Wegener? What was his hypothesis? - Alfred Wegener was a scientist who proposed that the continents slowly drifted to their present-day locations over millions of years. Continental drift is the idea that continents are moving very slowly, parallel to Earth’s surface 37. What were the 4 types of evidence presented by Alfred Wegener? Explain each one. a. the geographic fit of the continents: Wegener said that the continents fit together like puzzle pieces. 6 NAME: ____________________________ Class: ______ Midterm Date: ________________ b. Fossils: Similar plant and animal fossils were found on continents that are now far apart, telling us that they used to be connected millions of years ago. c. rock types/mountain ranges: Similar rocks and mountains were found on continents that are now far apart. d. ancient climate evidence: Areas that now have hot climates used to have cold climate. Areas with cold climates today used to have hot climate. 38. What was the seafloor-spreading hypothesis about? Explain. • • Explains continental drift hypothesis Seafloor age increases as distance from the mid-ocean ridge increases. • Convection currents bring hot materials in the mantle, toward the surface, causing magma to form • Magma flows out as lava through cracks along the ridge. • When lava cools, it forms new seafloor. • The seafloor moves sideways, away from the center of the M.O.R. 39. Mid-Ocean Ridges: Where are the old rocks? Where are the young rocks? The older rocks are away from the M.O.R. The new rocks are right next to the M.O.R. 40. Plate movement at divergent boundaries. Divergent: Lithospheric plates pull apart. 41. Plate movement at transform boundaries. Transform: Both plates slide horizontally past one another. 42. Plate movement at convergent boundaries. Convergent: Lithospheric plates move toward each other. 7 NAME: ____________________________ Class: ______ Midterm Date: ________________ 43. Define tension. Tension: When two plates are moving apart. The rocks are stretched and they become thinner. 44. Define shear. Shearing: When rocks slide horizontally next to each other. There is no change in thickness. 45. Define compression. Compression: Two plates are moving toward each other. Rocks are squeezed together and become thicker. 8