Earth Flashcards
What is the source of all our resources? Examples
Earth : Metal ores from rocks and fossil fuel
Name three fossil fuels
Coal, crude oil and natural gas
Plastics is made from what?
Crude oil
Fossil fuels are made from what?
Fossil fuels are made from the remains of dead plants and animals buried in the Earth’s crust for millions of years
Are Earth’s resources limited?
Yes
Why is recycling important?
Recycling is important because we have to save earth’s limited resources by reusing the materials.
Define Recycling
Recycling means taking old, unwanted products and using the materials to make new products.
List advantages of recycling
- Saves Earth’s limited resources
- Saves energy
- Saves money
- Less rubbish in landfill sites
If we do not recycle aluminium …
- More aluminium ore would have to be mined.
- Expensive to mine.
- Uses lots of energy to mine.
- The Aluminium transport and extraction uses more energy.
- It then costs money to send the used aluminium to landfill.
Name the layers of earth from inside to outside
- Inner core
- Outer core
- Mantle
- Crust
Inner core …
Inner core is a solid made up of iron and nickel.
The temperature is 5500 degrees C same as the Sun.
Outer core …
Outer core is a liquid made up of iron and nickel
Outer core is magnetic
Mantle …
Mantle is semi solid and liquid
Crust …
Crust is a thin layer of solid rock
Tectonic plates …
The crust and the upper mantle is cracked into a number of large pieces
When tectonic plates move suddenly, what happens?
Earth quakes
What often happens, where two tectonic plates meet?
Volcanoes and earth quakes
What are the three different types of rock in earth?
- Igneous rocks
- Sedimentary rocks
- Metamorphic roaks
What are igneous rocks?
The igneous rocks are formed from magma (melted underground rock) which is pushed through the crust - often through volcanoes.
What are the two types of igneous rocks?
Extrusive rocks: cooled fast above ground with small crystals e.g: Basalt
Intrusive rocks: cooled slowly under ground with large crystals e.g: Granite
How are sedimentary rocks formed?
Igneous rocks are weathered and eroded and sediments are transported by rain into lakes and seas.
Sedimentary rocks are formed from layers of sediments laid down in lakes or seas over million of years. Fossils can also form in the sedimentary rocks. Fossils are long dead remains of plants and animals.
The age of the rock can be calculated from the fossils.
Example: limestone. chalk and sandstone
How are metamorphic rocks formed?
Metamorphic rocks can be formed from igneous and sedimentary rocks, when heat and pressure is applied on the rocks over a long period of time.
Metamorphic rocks may have tiny crystals and some layers.
Example: marble, slate, schist
Rocks are made from what?
Rocks are made from minerals.
Minerals are made from elements and compounds.
Explain how metamorphic rocks can become igneous rocks?
Metamorphic rocks can melt into magma and then magma can cool down into igneous rocks.
Explain rock cycle
Rock cycle
- Weathering and erosion breaks down igneous rocks into smaller bits
- Transportation by rain
- Deposition of sediment
- Burial/compression/cementation
- Sedimentary rocks are formed
- Intense heat/pressure sedimentary rocks and igneous rocks turn into metamorphic rocks
- Metamorphic rocks melt and change to magma
- Magma cools down and igneous rocks are formed
- Weathering and erosion again.
What are the two different types of weathering?
- Onion skin weathering
This happens when the sun warms up the surface of the rock by day and by night it cools down. This causes the surface to expand and contract, and eventually it breaks away like peeling an onion.
- Freeze thaw weathering
When water freezes, it expands. If this happens in a crack in a rock, it can make the crack bigger. After freezing and thawing many times, bits break off.
Explain how the layers of sediment under the sea will be turned into rock.
The sediment layers are cemented together by other minerals and when pressure is applied turn into sedimentary rocks. Fossils can also form in the sediments.
Why is carbon an important element?
Carbon is an important element because it is part of all living things.
Explain carbon cycle
Carbon dioxide is in the air
Plants and algae absorb carbon dioxide for photosynthesis and make carbohydrates, proteins and fats
Animals eat plants - carbon is transferred
When plants and animals respire, carbon dioxide is released into the air
When plants and animals die they end up in the soil
Animal excretion ends up in the soil
Decomposers eat plant and animal remains and animal excretion
When decomposers (bacteria and fungi) in the soil respire carbon dioxide is released into the air
Dead plants and animals become fossil fuel after millions of years
Fossil fuel combustion releases carbon dioxide into the air
Define atmosphere
The gases that surround a planet make up that planet’s atmosphere.
Which gas is the highest concentration in the atmosphere?
Nitrogen 78%
What is the percentage of oxygen in earth’s atmosphere?
Oxygen 21%
What is the percentage of carbon dioxide in the atmosphere?
Carbon dioxide 0.04%
What are the gases in the atmosphere?
Nitrogen 78%
Oxygen 21%
Carbon dioxide 0.04%
Water vapour and other noble gases small amounts
What are the main reasons for increase in carbon dioxide levels in the atmosphere?
- Burning of fossil fuels to power cars and to produce electricity releases carbon dioxide
- Deforestration - Less carbon dioxide is removed from the trees through photosynthesis
What are the disadvantages of recycling?
- Capital costs high for the recycling plants
- Recycling sites are unhygenic, unsafe, unsightly and may result in pollution and dieseases
- Products made from recycled materials might be low in quality and might not be durable
- Recycling is not widespread - Industries are not recycling locally and globally
How does carbon dioxide contribute to global warming?
Carbon dioxide is a green house gas. It traps the sun’s energy in the atmosphere and makes the earth warmer resulting in increase in earth’s temperature.
Define global warming
Global warming is increase in earth’s temperature due to greenhouse gases trapping the sun’s heat in the atmosphere
What are the effects of global warming?
- The earth’s climate is changing. The earth’s temperature is increasing
- Glaciers and ice sheets in Greenland and Antarctica are melting
- Sea levels are rising
- Coastal areas are flooding
- Extreme weather: Storms, droughts more frequent
Give two things we get from crude oil
Petrol and diesel
Explain why recycling materials means we can burn fewer fossil fuels.
Recycling uses less energy so fewer fossils need to be burned.
What is the role of photosynthesis in the carbon cycle?
Carbon dioxide is absorbed from air during photosynthesis.
What gas is most of the atmosphere made of?
Nitrogen 78%
What is a greenhouse gas? Give one example
Greenhouse gas absorbs sun’s energy and traps it in the atmosphere resulting in an increase in earth’s temperature.
Example: Carbon dioxide, methane, water vapour and nitrous oxide
Why might global warming cause sea levels to rise?
Due to increase in earth’s temperature glaciers and ice sheets in Antartica and Greenland will melt and result in sea level rises.
Give four advantages of recycling materials over making them from scratch
- Not deplete earth’s limited resources.
- Less energy
- Saves money
- Less rubbish in landfill sites
List two decomposers
Mushrooms and earth worms
Describe the role of the decomposers in the carbon cycle
The decomposers feed on dead plant and dead animal remains and animal excretion and release carbon dioxide when they respire
Explain how the role of green plants in the carbon cycle is different to that of decomposers
Plants absorb carbon dioxide from the atmosphere for photosynthesis whereas decomposers release carbon dioxide into the atmosphere when they respire
Name the layers within Earth’s atmosphere from the nearest to the furthest
- Troposphere - weather
- Stratosphere - ozone layer solar radiation
- Mesosphere - meteors burn in this layer
- Thermosphere - satellites & aurora
- Ionosphere - link in the chain of Sun-Earth interaction; radio communication possible
- Exosphere - upperlimit
Give details for Troposphere
Troposphere
- starts from the earth’s surface
- most dense
- almost all weather is in this region
- 8-14.5km high
Give details for Stratosphere
Stratosphere
- starts above Troposphere
- 50km high
- the ozone layer, which absorbs and scatters the solar radiation is in this layer
Give details for Mesosphere
Mesosphere
- starts above Stratosphere
- 85 km high
- meteors burn in this layer
Give details for Thermosphere
Thermosphere
- starts above Mesosphere
- 600 km high
- aurora and satellites occur in this layer
Give details for Ionosphere
Ionosphere
- is an abundant layers of electrons and ionized atoms and molecules
- from 48km above the surface to the edge of space at about 965 km, overlapping into the Mesosphere and Thermosphere
- this dynamic region grows and shrinks based on solar conditions
- it is further divided into sub-regions D, E, F based on what wavelength of solar radiation is absorbed
- it is a critical link in the chain of Sun-Earth interactions
- this region is what makes radio communication possible
Give details for Exosphere
Exosphere
- upper limit of our atmosphere
- it extends from the top of the Thermosphere upto 10,000 km
