Rocks and Weathering End of Topic

What is an igneous rock?

An igneous rock is a type of rock that forms from the solidification of molten rock material, such as lava or magma. It can be classified into two types: intrusive and extrusive, depending on where it solidifies. Intrusive igneous rocks form when magma cools and solidifies slowly beneath the Earth's surface, while extrusive igneous rocks form when lava cools and solidifies quickly on the Earth's surface.

What is a metamorphic rock?

A metamorphic rock is a type of rock that has been transformed from its original state by heat, pressure, or chemical processes. This transformation can occur due to changes in temperature and pressure deep within the Earth's crust, or as a result of contact with hot fluids or magma. Examples of metamorphic rocks include marble, slate, and gneiss.

What is a sedimentary rock?

A sedimentary rock is a type of rock that forms from the accumulation and cementation of sediment, which can include pieces of other rocks, minerals, and organic matter. Examples of sedimentary rocks include sandstone, limestone, and shale. They are carried by rivers as they begin to form.

What are the properties of igneous rocks?

* Hard
* Contain crystals
* Porous

What is an extrusive igneous rock?

Magma that has erupted and cooled quickly outside.

What is an intrusive igneous rock?

Magma that has cooled slowly deep underground.

What are the properties of a sedimentary rock?

* Layers
* Soft
* Porous
* Malleable

What are the properties of metamorphic rocks?

* Non-porous
* Hard
* Ductile

What is physical weathering?

Where rocks break down. Weathering often leads to erosion which breaks down rocks even further. This makes them easier for wind and water to carry them away.

What is freeze-thaw weathering?

Water gets into the cracks of rocks. When the water freezes, it expands and the crack enlarges until it breaks apart.

What is exfoliation?

Cracks form that are parallel to the surface. These rocks contract during the night and layers of rock begin to break off. This is also called onion skin weathering?

What is acid rain released from?

* Sulphur Dioxide (SO2) - released when sulphur impurities in coal react with oxygen
* Nitrogen Oxides (NOx) - produced from the reaction of nitrogen and oxygen in engines

What rocks are used for building? Why?

The main rocks used to build houses are:

* Sandstone
* Limestone
* Slate tiles

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Sandstone and limestone are sedimentary rocks. This makes them good for bricks as they are easy to cut but still hard enough to withstand things.

Slate is waterproof and can be split into many layers. It also doesn’t react to acid at all. THis maks it good for roofing tiles.

Why do ores occur?

Rocks are usually too reactive to exist in the ground on their own, so instead they combine with other elements (usually sulphur or oxygen) to create a compound called an ore.

A few metals are so unreactive (gold and silver) that they are pure metals.

What different extraction methods are used for different metals?

* Gold and silver are found in the ground and are so unreactive that they do not need further extraction.
* Most metals are found combined with other elements and therefore need to be separated. We do this with either displacement or electrolysis. This is where you use electricity to make a chemical change.

What are polymers?

Polymers are substances made up of large molecules called ‘macromolecules’. These macromolecules are made up of smaller molecules called monomers. They make up the bases of many minerals.

What is a composite?

A composite is a combination of two elements with different physical and chemical properties.

What is a ceramic?

A ceramic is a material which is neither metallic nor organic. They are made of either metal or non-metal compounds which eventually harden.

What is the rock cycle?

the rock cycle is how rocks form.

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* Start with magma. Metamorphic rocks are created over time with harsh pressure in magma below a volcano.
* Intrusive magma rocks are made inside magma too, however do not go through as much pressure and they end up cooling.
* When a volcano erupts, extrusive igneous rocks can alo be produced.
* Next, weathering and erosion occurs, and this is where sedimentary rocks form.
* This cycle continues.

What are fossil fuels made up of?

Hydrocarbons. This means they contain both hydrogen and carbon. They burn very well which is why they are good as fuels.

How does coal form?

* Plants die
* Layers eventually build up over them
* After millions of years of pressure, coal is produced.

How does oil form?

* Plants and animals die
* Layers eventually build up over them
* After millions of years, oil is produced.