C9 Chemistry of the atmoshpere

Question 1

what are the 2 main gases and 4 sub gases in the atmosphere?

Answer 1

2 main:
nitrogen
oxygen
4 sub:
carbon dioxide
water vapour
helium
methane

Question 2

what is the percentage of nitrogen in the atmosphere?

Answer 2

78%

Question 3

what is the percentage of oxygen in the atmosphere?

Answer 3

20%

Question 4

what is the percentage of the 4 sub gases in the atmosphere?

Answer 4

<1%

Question 5

what gas wasn’t present in the Earth’s early atmosphere?

Answer 5

oxygen

Question 6

how did co2 decrease due to the forming of oceans? (summary)

Answer 6

some co2 dissolves in the ocean to from sediment and was locked up in rocks

Question 7

how did co2 decrease due to plants? (summary)

Answer 7

plants developed the ability to photosynthesise which also increases oxygen

Question 8

how did co2 in the atmosphere get into plankton in the ocean to form crude oil and natural gas that is then extracted?

Answer 8

-plankton falls into the seabed
-layered in layers of sediment, mud and sand
-caprock traps natural gas
-get compressed under extreme heat and pressures over millions of years
-crude oil is extracted from seabed

Question 9

what does increased co2 cause a reaction between it and __?

Answer 9

seawater

Question 10

what 2 things does the reaction between co2 and seawater produce?

Answer 10

insoluble carbonates and soluble hydro carbonates

Question 11

where are insoluble carbonates that are the by-product of the reaction between co2 and seawater?

Answer 11

deposited as sediment

Question 12

where are soluble hydro carbonates that are the by-product of the reaction between co2 and seawater?

Answer 12

dissolved in seawater

Question 13

what are the 2 places where “locked-up” carbon is trapped?

Answer 13

sedimentary rocks or fossil fuels

Question 14

from what did the trapped carbon from sedimentary rocks come from?

Answer 14

volcanic activity

Question 15

from what did the trapped carbon from fossil fuels come from?

Answer 15

combustion - burning co2

Question 16

how did the co2 in the atmosphere get into coal?

Answer 16

-plants in swamps
-these die and land on the muddy surface
-they are covered in layers of mud
-they are compressed in extreme heat and pressures over millions of years
-the coal then is mined from the land

Question 17

explain how carbon monoxide is produced when petrol is burned in car engines

Answer 17

it is a by-product due to incomplete combustion as there is insufficient oxygen available

Question 18

suggest 2 reasons why the maximum percentage of carbon monoxide has been decreased for newer cars

Answer 18

1) carbon monoxide is toxic
2) there is greater public awareness about pollution

Question 19

give one reason for having a maximum allowed percentage of unburned hydrocarbons in exhaust fumes

Answer 19

can cause respiratory diseases

Question 20

give 2 affects of atmospheric pollution which are reduced by using catalytic convertors

Answer 20

1) acid rain
2) global dimming

Question 21

give one reason why it is difficult to produce models for future climate change

Answer 21

the Earth’s climate keeps on changing due to human’s activities, it would depend on these carbon emissions

Question 22

describes how carbon dioxide helps to maintain temperatures on Earth

Answer 22

-carbon dioxide is a greenhouse gas
-short wavelength radiation from the sun can be reflected on the surface of the Earth
-then these turn to long wavelength radiations but cant go out of the atmosphere
-c02 absorbs this and its re-directed in all directions

Question 23

What type of rock is made from layers of ocean sediment cemented together?

Answer 23

sedimentary rocks

Question 24

Over millions of years, plant deposits have been buried and compressed, forming a type of sedimentary rock. What do we call this rock?

Answer 24

coal

Question 25

What does the electric spark represent that would have existed on the early Earth?

Answer 25

lightning

Question 26

Did carbon dioxide levels in the atmosphere increase or decrease when sedimentary rocks and fossil fuels that contain carbon were formed?

Answer 26

deacrease

Question 27

Earth's atmosphere was formed billions of years ago. What released the gases into the atmosphere?

Answer 27

volcanos

Question 28

Name the process that produced the oceans from the water vapour in Earth's early atmosphere.

Answer 28

condensation - The Earth cooled, causing the water vapour to condense into liquid water.

Question 29

What sedimentary rock is made up of mainly calcium carbonate?

Answer 29

limestone

Question 30

Coal and oil are two examples of fossil fuels. What is a third?

Answer 30

gas

Question 31

One theory states that the Earth's early atmosphere was mainly carbon dioxide with small amounts of water vapour, ammonia and which other gas?

Answer 31

methane