Materials from the Earth Flashcards
how are igneous rocks formed
igneous rocks are formed when magma or lava solidifies
what are igneous rocks made of? what does this do?
they are made of interlocking crystals which makes them hard and resistant to erosion.
how does the rate of cooling affect the size of igneous rocks
if the rock cools quickly they have small crystals (basalt). if the rock cools slowly they have large crystals (granite)
give two examples of sedimentary rocks
chalk and limestone
how are sedimentary rocks formed
formed when layers of sediment are compacted/squashed over a long period of time by being buried under more layers.
give two features of sedimentary rocks
erode more easily than igneous and metamorphic rocks. and they may contain fossils
give an example of a metamorphic rock
marble
how are metamorphic rocks formed
formed from existing rocks by the action of heat (being being buried or from nearby magma) and pressure which causes new interlocking crystals to grow
how is marble formed
marble is formed from chalk or limestone. it is a natural form of calcium carbonate
what is limestone used for
making buildings, roads, railways.
what is limestone mostly made of
calcium carbonate
what is calcium carbonate used to make
it is used to make glass, cement and concrete
how do we use limestone to make cement and glass
limestone is heated when making cement and glass
describe the thermal decomposition of limestone(calcium carbonate)
the heat decomposes the calcium carbonate to from calcium oxide and carbon dioxide.
give the word equation of the thermal decomposition of calcium carbonate
calcium carbonate > calcium oxide + carbon dioxide
give 4 advantages of quarrying limestone
1) it is an important raw material
2) quarries provide jobs in the countryside
3) some limestone is exported to other countries, which helps the UK economy
4) jobs in quarries also help local economies, because the workers spend their money in local shops and businesses
give 4 disadvantages of quarrying limestone
1) quarries produce dust and noise pollution
2) digging a quarry destroys habitats for wildlife
3) quarries spoil the scenery
4) lorries taking the limestone away cause extra traffic, noise and pollution
Describe the ease of thermal decomposition of different metal carbonates
calcium carbonate (hardest to decompose), zinc carbonate, copper carbonate (easiest to decompose).
give 3 features of atoms
1) atoms are the smallest particles of an element that can take part in chemical reactions
2) during chemical reactions, atoms are neither created nor destroyed
3) during chemical reactions, atoms are rearranged to make new products with different properties from the reactants
Describe the effect of water on calcium oxide
heat is released. the mixture fizzes, steam is given off and the calcium oxide crumbles to a white powder of calcium hydroxide. if more water is added to the reactants, the calcium hydroxide dissolves to form a solution called limewater
what happens when calcium hydroxide is dissolved in water
calcium hydroxide dissolves to form a solution called limewater
what is a precipitate reaction
a precipitate reaction happens when two soluble substances react together to form a product that is insoluble. the insoluble product is the precipitate.
what does a precipitation reaction in a sealed container show
it shows that the total mass before and after a reaction does not change.
how can calcium oxide, calcium hydroxide and calcium
carbonate be used
they can all be used to neutralise acidic compounds. some soils are acidic. farmers use calcium compounds to neutralise the acidity so their crops will grow better.
explain why gases emitted by coal-fired power stations need to be cleaned up, and how calcium carbonate can do this.
the waste gases from coal-fired power stations contain sulfur dioxide and nitrogen oxides, which are acidic gases. these gases cause acid rain if they get into the atmosphere. wet, powdered calcium carbonate is sprayed into the waste gases to neutralise them.
