Page 149 - Knowledge Organiser Yr8 24-25

Knowledge Base: Science 8.11 Earth and Atmosphere Year 8
1. Structure of the earth
1.1
Label the four layers of the earth
1.2
Which layer of the earth is made up of huge plates which move very slowly?
Crust
2. Types of Rock – Part 1
2.1
Name the three types of rock?
Sedimentary, Igneous and Metamorphic
2.2
Give the 4 stages of the formation of sedimentary rocks
1. Weathering
2. Erosion and Transport
3. Deposition
4. Compaction & Cementation
2.3
Weathering breaks rocks into smaller pieces called ________
Sediments
2.4
Describe the three types of weathering of rocks.
1. Physical – rocks being broken by freezing and thawing of trapped water or the action of water.
2. Chemical – rocks being broken up because substances in rainwater, rivers and seawater or the air, react with the minerals in the rocks
3. Biological – rocks being broken up by plants or animals
2.5
What is erosion and transport of rocks?
Movement of sediments away from their rock by water, ice, wind and gravity
2.6
What is the name of the process in which small pieces of rocks sink to the bottom of seas and oceans?
Deposition
2.7
What type of rock is made from layers of ocean sediment cemented together?
Sedimentary
2.8
What would you observe when looking at sedimentary rock?
Made up of different grains arranged in layers
1.3 How thick is the crust?
1.5 What state is the rock in the mantle?
Approx. 8-40m thick
Semi-liquid
1.4
Which layer makes up around 85% of the earths volume?
Mantle
1.6
Which layer of the earth is made mainly of iron with some nickel?
Inner and Outer Core
1.7
What is the name of the semi- molten rock that forms the mantle?
Magma
1.8
What kind of currents in the mantle cause the tectonic plates to move?
Convection currents
1.9 Which part of the earth is the hottest?
1.10 Which part of the earth is liquid?
Inner core Outer core
1.11
From which layer do we mine useful compounds and elements?
Crust
1.12
How do scientists know about the structure of the mantle, outer core and inner core?
Studying shock waves from earthquakes; examining materials brought to the surface by volcanos
2.9 Name a common sedimentary rock.
Limestone, Sandstone
2.10
Why are sedimentary rocks used for building materials?
They are soft and easy to shape into blocks.
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