6 th Grade Review

Chapter 2

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

 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

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

 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

Chapter 3

 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

Chapter 4

 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

 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

Chapter 5

 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

 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

Chapter 11

 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.

 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

 Troposphere – inner layer of the atmosphere where people live and weather occurs  Stratosphere – 2 nd 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

Chapter 13

 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