Chemistry In Our World and materials from Earth Flashcards
What gases are released from volcanoes
Carbon dioxide, nitrogen, methane, ammonia, water vapour
How did volcanoes lead to water
When they erupt water vapour is released and as the earth cooled the water vapour condensed and gradually formed oceans
Why hasn’t Mars or venues atmosphere changed like ours
Life on Earth meant different gases were taken in and released, changing the atmosphere
Why do scientists think there was almost no oxygen on earth billions of years ago
Some of the oldest iron compounds on earth can only form where there isn’t oxygen
Where did most of the carbon dioxide in the early atmosphere gone after oceans formed
It was absorbed into the oceans. About half of it
How is limestone formed
Sea creatures used the co2 in the water to make their shells out of calcium carbonate. When they died their shells sunk and formed layers, over time the heat and pressure turned the shells into limestone
How was carbon dioxide removed using plants
Plants photosynthesis which removes the co2 and releases oxygen
Gas percentages in the atmosphere
N 78.00 O 21.00 Argon 0.90 CO2 0.04 Other traces
What are igneous rocks
Rocks from the cooling of lava
What is molten rock called
Magma
What is surface Magma called
Lava
What determines the size of crystals in igneous rocks
Cools fast, smaller crystals
Cools slowly, larger crystals
Example of an igneous rock
Granite
What are sedimentary rocks made of
Sediment from other rocks caused by erosion or remains of organisms. Over millions of years, layers build up and pressure and heat forms the rock
How are igneous rocks made
Through the cooling of magma/lava
Example of sedimentary rock
Chalk, limestone
What are metamorphic rocks made of and how are they made
Made up of other rock that has been put under lots of pressured and heat to form new crystals and morph into another rock
Example of metamorphic rock
Marble, made from chalk or limestone
What is the main compound in chalk and limestone
Calcium carbonate, from shell animals
Why does sedimentary rock erode easier than igneous or metamorphic
Unlike igneous or metamorphic it doesn’t have interlocking crystals that help hold it together so they aren’t as hard
Uses of limestone
Making glass
Cement
Buildings
Making alloys
Advantages and negatives to quarries
Advantages:
Gives us useful materials
Gives people jobs in places where jobs are difficult to find
Negatives:
Lots of noise
Extra traffic from transport Lorries
Often built in pretty places like Peak District and they look ugly
What usually happens to used up quarries
The owner often turns it into a nature reserve or farmland
Thermal decomposition of Calcium carbonate
Calcium carbonate –> carbon dioxide +calcium oxide
How is cement made
Heating limestone and powdered clay in a rotating kiln then grinding the mixture to make cement
Uses of cement
Used to make mortar which is used to hold bricks together
Used to make cement after mixing it with water ,sand and rocks, used to make buildings and bridges
How is glass made
Limestone is heated with sand and sodium carbonate to form molten glass
How is limewater made
Calcium carbonate is heated to make calcium oxide and carbon dioxide
Water is added to calcium oxide which causes and hot reaction and forms a white compound called calcium hydroxide
More water is added to this compound and it dissolves to make lime water
What is limewater called
Calcium hydroxide solution
Why does limewater go cloudy when carbon dioxide is passed through
It reacts and calcium carbonate (a precipitate) is formed which is white. So it looks cloudy
How can farmers neutralise acidic soil
Spraying powdered calcium carbonate/oxide/hydroxide onto the soil as it’s an alkali
How do power stations stop acidic gases (sulphur dioxide and nitrogen oxides) from escaping and forming acidic rain
They are stored and powdered calcium carbonate is sprayed through them which neutralised them
