chemistry of the atmosphere

Question 1

why was the early earths atmosphere mainly co2 and h20?

Answer 1

because the earth was covered in volcanoes which erupted and produced those gases

Question 2

what caused the water vapour to condense and what did this lead to?

Answer 2

the volcanoes began to erupt less causing the earth to cool which allowed the water vapour to condense leading to oceans being formed and rain occurring.

Question 3

what did the formation of oceans lead to?

Answer 3

the rain allowed algae and plants to evolve and grow, which could photosynthesize which produced o2 and lowered co2 levels, the formation of oceans also reduced co2 in the atmosphere as the co2 dissolved in the water.

Question 4

state three reasons why co2 reduced over time

Answer 4

as the earth cooled the water vapour condensed creating oceans which caused co2 to dissolve in the water
co2 got trapped in sedimentary rock as it formed
plants and algae evolved which could photosynthesise, this took co2 in to make glucose and produced oxygen

Question 5

how did oxygen remove methane and ammonia from the atmosphere?

Answer 5

the oxygen caused combustion of methane and ammonia which removed them from the atmosphere

Question 6

how long ago did the earth form?

Answer 6

about 4.6 billion years ago

Question 7

what is the proportion of gases in our atmosphere today?

Answer 7

oxygen-21%
nitrogen-78%
argon-0.9%
co2-0.04%
others-trace

Question 8

explain the increase in nitrogen in the early atmosphere and today?

Answer 8

as plants died nitrogen was produced by the bacteria during the decay of dead organisms which produced nitrogen through a reaction with oxygen.nitrogen builds up in the atmosphere because it is unreactive

Question 9

what is combustion?

Answer 9

when an element/compound reacts with oxygen and releases heat energy(exothermic)

Question 10

what is complete combustion?

Answer 10

when fuels burn in a plentiful supply of oxygen

Question 11

what are the products of complete combustion?

Answer 11

carbon dioxide and water

Question 12

methane + oxygen….

Answer 12

=co2+h2o

Question 13

what is incomplete combustion?

Answer 13

when fuels are burnt in a limited supply of oxygen

Question 14

what are the products of incomplete combustion?

Answer 14

carbon monoxide and water

Question 15

what is the formula for carbon monoxide?

Answer 15

CO

Question 16

give one use of a combustion reaction

Answer 16

to make fuels as combustion releases lots of energy when burned with oxygen

Question 17

give 3 properties of alkanes?

Answer 17

-shorter alkanes are more volatile(evaporate more easily)
-longer alkanes are more viscous
-shorter alkanes are more flammable

Question 18

give a trend of the carbon chains?

Answer 18

as the length of the carbon chain increases boiling point increases

Question 19

name 4 pollutants

Answer 19

-sulfur dioxide
-carbon monoxide
-nitrogen oxides
-carbon dioxide

Question 20

what are particulates and how are they formed?

Answer 20

solid particles of carbon(soot) which are formed during incomplete combustion

Question 21

give two problems particulates can cause?

Answer 21

cause respiratory problems when inhaled
cause global dimming-forms smog which reflects sunlight back into space so less light reaches earth

Question 22

how is carbon monoxide formed?

Answer 22

during incomplete combustion

Question 23

what problems can carbon monoxide cause?

Answer 23

is dangerous-lead to death-restricts oxygen transported around body as it binds to haemoglobin when it diffuses into our blood

Question 24

how is sulfur dioxide formed?

Answer 24

when hydrocarbons we burn have impurities in them like atoms of sulfur which then becomes oxidised

Question 25

give two problems sulfur dioxide can cause?

Answer 25

-acid rain-mix with clouds and dissolve to form dilute sulfuric acid(damage buildings and plants) -respiratory problems

Question 26

how is nitrogen oxide formed?

Answer 26

when nitrogen and oxygen from the air react together-only happens in internal combustion engines

Question 27

give two problems nitrogen oxide causes?

Answer 27

-acid rain -smog formation-can be harmful to health-respiratory problems

Question 28

name three greenhouse gases?

Answer 28

carbon dioxide,methane,water vapour

Question 29

give 2 causes of global warming linked to carbon dioxide?

Answer 29

-burning lots of fossil fuels for energy,which will release co2 -deforestation for farming/arable land-this causes less photosynthesis to occur meaning less co2 is taken in by plants

Question 30

give 2 causes of global warming linked to methane?

Answer 30

-increased farming-farm animals produce methane during digestion which is then released into the atmosphere -producing huge amounts of waste and landfill-releases methane as it decomposes

Question 31

what is a consequence of global warming?

Answer 31

this will lead to climate change

Question 32

what is climate change?

Answer 32

climate change is the effects of global warming on the climate

Question 33

what is the atmosphere?

Answer 33

the atmosphere is a layer of gases surrounding the earth that is held in place by gravity

Question 34

how are global warming and climate change different?

Answer 34

-global warming refers to the overall increase in the earths temperature -whereas climate change is a consequence of global warming and refers to the effects on the climate,such as large scale shifts in weather patterns

Question 35

give an effect of global warming? (flooding)

Answer 35

-sea levels will rise as higher temperatures cause the ice caps to melt which will increase the volume of water in the ocean,also water expands when it is heated and so this will lead to a further increase in the volume of water in the oceans -all of this will lead to seasonal flooding or the submersion of entire islands

Question 36

give an effect of global warming?(weather)

Answer 36

-severe weather events such as droughts or hurricanes will become more common and severe

Question 37

why will species become extinct due to global warming?

Answer 37

species are no longer perfectly adapted to their environments which are rapidly changing due to global warming meaning they may struggle to survive and could potentially become extinct.

Question 38

give stage 1 of the greenhouse effect

Answer 38

solar radiation from the sun passes through the atmosphere and hits the earth

Question 39

stage 2 of the greenhouse effect?

Answer 39

some of this energy is reflected straight back towards space and some of it is absorbed by the earth and is then re-emitted towards space

Question 40

stage 3 of the greenhouse effect?

Answer 40

some of the energy makes it all the way to space but much of it is absorbed by small molecules called greenhouses gases

Question 41

stage 4 of the greenhouse effect?

Answer 41

these molecules then re-emit the energy and the whole process of absorption and emission happens over and over again

Question 42

stage 5 of the greenhouse effect?

Answer 42

this trapped energy keeps the atmosphere warmer and more stable than it would be otherwise

Question 43

what is a carbon footprint?

Answer 43

the total amount of co2 and other greenhouse gases emitted over a products,service or events entire lifecycle

Question 44

what is one benefit of calculating the carbon footprint of something?

Answer 44

it can help us identify the most polluting activities and allow us to try and reduce their emissions

Question 45

three factors you need to take into account when finding the carbon footprint of something?

Answer 45

-how the raw materials were sourced -the manufacturing process -how its disposed of

Question 46

three general ways to reduce the carbon footprint of an object

Answer 46

-create it using fewer or more sustainable raw materials -use a more efficient manufacturing process(uses less energy/waste) -use renewable energy sources