C1 - topic 1 - the earth sea and atmosphere Flashcards
when things eventually began to cool down what happened?
a thin crust formed
when a thin crust formed what kept occurring?
volcanoes kept erupting
what gases do volcanoes release?
Carbon dioxide
water vapour
small amounts of other gases
according to the theory of evolution, the early atmosphere was mainly what?
Carbon dioxide - co2
what is the symbol for carbon dioxide?
co2
what gas was there virtually none of in the early atmosphere?
oxygen
when did oceans form?
when water vapour released through the eruption of volcanoes condenses
what is phase 2 of the evolution of the atmosphere?
green plants evolving which produces oxygen
what dissolved into the oceans?
Carbon dioxide
when did marine organisms develop?
after oceans formed
what did the marine organisms take in?
Carbon dioxide
how was Carbon dioxide locked up in carbonate rocks?
marine organisms died when they were then buried under layers of sediment
were green plants happy in the carbon dioxide atmosphere?
yes
how did green plants affect the level of gases in the atmosphere?
they removed cabin dioxide and produced oxygen through the process of photosynthesis
what is phase 3 of the evolution of the atmosphere?
ozone layer was created which allows the evolution of the complex animals
what killed off some early organisms?
the build up of oxygen in the atmosphere
what did the build up of oxygen in the atmosphere allow?
more complex organisms to evolve and flourish
what did the build up of oxygen create?
the onzone layer
what does the ozone layer do?
block harmful rays from the sun and enable more complex organisms to evolve
what is the level of carbon dioxide left in the atmosphere?
very little
what is phase one of the evolution of the atmosphere?
volcanoes releasing gases
what is a human activity changing the atmosphere?
burning of fossil fuels
how did the burning of fossil fuels affect the atmosphere?
they released Carbon dioxide and as the world is becoming more industrialised, more fossil fuels have been burnt in power stations and car engines
what is a human activity that affects the atmosphere?
deforestation
how does deforestation affect the atmosphere?
it contributes to the Carbon dioxide levels as tress take in Carbon dioxide and release oxygen so when trees are cut down more Carbon dioxide is left in the atmosphere
what is a human activity that affects the atmosphere?
livestock farming
how does livestock farming effect the atmosphere?
release huge amounts if methane into the atmosphere
what gases do volcanoes release in today’s atmosphere?
sulfur dioxide
carbon dioxide
what does sulfur dioxide react with?
sunlight, water, oxygen and dust to form volcanic smog
why are the sources of information o. the evolution of the atmosphere limited?
no one was actually there at the time so it’s difficult to be precise about exactly how the atmosphere has changed - some of it is guess work
how have we learnt a lot about the atmosphere through Antarctic ice cores?
each year, a layer of ice forms
bubbles of air gets trapped inside then it’s buried by the next layer = the deeper the ice, the older the air
if you examine the bubbles in different layers, you can see his the air has changed
why do the measurements of air bubbles in Antarctic ice cores have to be ultra-precise?
changed between layers can be very very tiny
how can you investigate the proportion of oxygen in the atmosphere?
heat copper
how do you test the proportion of oxygen in the atmosphere?
heated copper reacts with oxygen to make copper oxide so the reaction uses up oxygen
heat excess coppe in a tube and pass air over it using two syringes
you can use the markets or the syringes to tell how much oxygen has been used up
to start with, if there is 100cm of air, how much will you end up with if you’re removing the oxygen?
about 80cm because 21% of the air is made up of oxygen
what are the percentages of gases in the atmosphere today
nitrogen = 78%
oxygen = 21%
other gases = small amounts
where has evidence for how the atmosphere evolved been found?
rocks and other sources
what gases were produced by volcanic activity in the earths early atmosphere?
water vapour
Carbon dioxide
describe how the oceans were formed?
volcanoes released water vapour which condensed as the atmosphere cooled
what has happened to the amount of carbon dioxide over time
decreased due to photosynthesis and oceans
how has the ocean helped to decrease the amount of carbon dioxide in the atmosphere?
marine organisms take in carbon dioxide and when they die they are buried beneath layers of sediment so the Carbon dioxide is ‘locked up’
how have played to and photosynthesis affected the amount of carbon dioxide in the atmosphere?
plants take in carbon dioxide and release oxygen during photosynthesis so it has helped decrease the level of carbon dioxide
what changed to the atmosphere occur because of burning fossil fuels and deforestation?
burning fossil fuels releases carbon dioxide
deforestation leaves carbon dioxide in the atmosphere as there is less trees to absorb it
what are the percentages of the gases in the earths current atmosphere?
nitrogen - 78%
oxygen - 21%
argon - 0.9%
carbon dioxide -0.04 %
could the early atmosphere support life as we know it?
no, because humans and complex animals couldn’t life with so little oxygen
which organisms cause an increase in oxygen and a decrease in carbon dioxide?
plants
are humans decreasing or increasing the amount of carbon dioxide in the atmosphere by burning fossil fuels?
increasing
does deforestation reduce or increase the amount of carbon dioxide absorbed from the atmosphere?
reduces
did volcanoes give out gases in the very early atmosphere?
yes
why is it difficult to be precise about the evolution of the atmosphere?
no one was around millions of years ago so we can only make guesses and theories
