Flashcards in Topic 2 - Materials From The Earth Deck (25)
What type of rock are limestone and chalk?
Limestone and chalk are easily
Broke away by wind, rain and waves
How are metamorphic rocks formed ?
They're formed by the action of heat and pressure on sedimentary rocks over long periods of one
The mineral structure and texture may have changed but the chemical composition is often the same as the original rock
As long as they don't melt they're classed as metamorphic
How is marble formed?
When limestone or chalk are broke down by very high temperatures and reforms as small crystals
How are igneous rocks formed?
When molten magma pushes up into the crust and cools and solidifies
They contain various different minerals in randomly arranged interlocking crystals
What are the two different types of igneous rocks?
Extrusive - cool quickly above ground forming small crystals
Intrusive - cool slowly underground forming big crystals
What can limestone be used for?
Buildings, statues, road surfacing
How is cement made?
Powdered limestone is heated in a kiln with powdered clay
How is concrete made?
By mixing cement with sand, water and gravel
How is glass made?
Heating limestone, sand and sodium carbonate until it melts
What environmental problems can quarrying limestone create?
- huge holes that permanently change the landscape
- quarrying processes make lots of noise and dust in quiet scenic areas
- destroys the habitat of animals and birds
- it needs to be transported away which causes noise and pollution
- waste materials produce tips
What are some useful uses of limestone?
- neutralising acidic soil
- houses, road
- neutralising sulfur dioxide in power station chimneys (cause of acid rain)
- quarrying provides jobs for people which improves the local economy and can lead to local improvements
- once quarrying is completed landscaping and restoration is normally required
How are sedimentary rocks formed?
- they're formed from layers of sediment laid dow in lakes and seas
- over millions of years the layers get buried under more layers and the weight pressing down squeezes out the water
a fluids flowing through the pores deposit natural mineral cement
Limestone is mainly
When heated limestone thermally decomposes to make
Calcium oxide and carbon dioxide
Thermal decomposition of carbonates make
Carbon dioxide and an oxide
How easily a carbonate thermally decomposes depends on
The stability of the metal carbonate
Calcium oxide reacts with water to make
Calcium hydroxide is an
Calcium hydroxide can be used
To neutralise acidic fields, it's quicker than calcium oxide
Calcium hydroxide dissolves in water to produce
Metals that are Unreactive don't form
Most metals form compiles which are found in
The earths crust
If a compound contains enough of the metal to make it worthwhile extracting it's called
A metal ore