6 th Grade Review

1. 6th Grade Review

2. Chapter 2

3. Layers of the Earth • Crust • Mantle • Outer Core • Inner Core • Pressure increases from Earth’s surface toward the center of Earth

4. Igneous • Extrusive – rock that is formed from magma beneath Earth’s surface • Basalt – most common extrusive rock • Intrusive – rock that formed from lava that erupted onto Earth’s surface • Granite – most common intrusive rock

5. Fossils – small particles of rock or the remains of living things that make up sedimentary rocks Metamorphic rock – can form from any rock through heat and pressure

6. Hardest known mineral – diamond • Softest know mineral – talc • Gem – a gemstone that is cut and polished • Mineral – always a solid because it has a definite shape and volume

7. Chapter 3

8. Pangaea – the name of the supercontinent that existed millions of years ago • Wegner supported the idea where the continents were joined in this one land mass • Geologists relied on evidence from fossils to study Earth’s interior • Sonar – technology used by scientists in the mid-1900s to map the mid ocean ridge • Convection currents – in the mantle, heat is transferred as soft rock which flows slowly in this cycle

9. Chapter 4

10. Earthquakes – caused by seismic waves that travel through Earth • P waves (Primary) – seismic waves that arrive at the surface first and move by compressing and expanding like an accordion • S waves (Secondary) – seismic waves that vibrate from side to side and up and down through solids only • Moment magnitude scale – scale used to tell how much damage an earthquake has done to homes and other buildings

11. Tension – the stress force that pulls on the crust where two plates are moving apart • Compression – the squeezing together of rocks by stress • Hanging wall – the block of rock that lies above a fault • Foot wall – the block of rock that lies below a fault

12. Chapter 5

13. Ring of Fire – major volcanic belt in the Pacific Ocean • Island arc – string of islands which can form from the collision of two oceanic plates • Quiet Eruption – low silica content in magma • Explosive Eruption – high silica content in magma

14. Cinder cone volcano – ash, cinders, and bombs build up in a steep pile • Composite volcano – tall, cone shaped mountains in which layers of lava alternate with layers of ash • Dome mountain – landform which is caused when magma forces the layers of rock to bend upward • Active volcano – erupting or may erupt in the future • Dormant volcano – volcano that is inactive but may become active in the future • Extinct volcano – volcano that is no longer active

15. Chapter 11

16. Barometer – used to measure air pressure • Thermometer – used to measure the average temperature • Celsius - 0° freezing point and 100° boiling point • Fahrenheit - 32° freezing point and 212° boiling point • Uneven heating of the atmosphere leads to differences in air pressure, which causes wind.

17. Conduction – heat transfer between two substances that are in direct contact • Convection – heat transfer between liquids • Radiation – heat transfer through electromagnetic waves • Scientists divide Earth’s atmosphere into four main layers, classified according to changes in temperature • Earths surface when heated radiates some energy back into the atmosphere as infrared radiation

18. Troposphere – inner layer of the atmosphere where people live and weather occurs • Stratosphere – 2nd layer where the ozone is located – absorbs most ultraviolet radiation • Mesosphere – middle layer which protects Earth from most meteors • Thermosphere – divided into two layers • Ionosphere – northern lights or aurora borealis occurs • Exosphere – where satellites orbit the Earth

19. Chapter 13

20. Cirrus clouds- very high feathery clouds • Cumulonimbus clouds – large towering clouds that are flat on top where thunderstorms come from also known as thunderheads • Tornadoes come from the same clouds • Drought – long period of less rainfall than normal, dry weather and may result in a shortage of water • Flash flood – sudden, violent floods that occur shortly after a storm