Chemistry of the Atmosphere

Question 1

What formed the early atmosphere?

Answer 1

Intense volcanic activity caused the release of gases that formed the early atmosphere during the first billion years

Question 2

When was the early atmosphere formed?

Answer 2

In the first billion years of the Earth’s history

Question 3

What was the early atmosphere made up of?

Answer 3

Mostly carbon dioxide, nitrogen, water vapour and small amounts of methane and ammonia (N, CH4 and NH3 from volcanoes)

Question 4

At the start of the Earth’s early atmosphere, what may it have been like?

Answer 4

Like the atmospheres of Mars and Venus today - mainly CO2, little to no oxygen gas

Question 5

How did the ocean form?

Answer 5

When the water vapour in the atmosphere condensed, it formed the oceans

Question 6

How was carbon dioxide removed from the early atmosphere?

Answer 6

It dissolved into the oceans and went through a series of reactions that formed carbon precipitates. These precipitates formed sediments on the seabed
Green plants and algae evolved and absorbed CO2 so they could carry out photosynthesis.

Question 7

How did carbon get trapped in fossil fuels and rock?

Answer 7

When plants, plankton and marine animals died, they fell to the seabed and got buried by layers of sediment
Over millions of years, they were compressed and formed sedimentary rock, oil and gas - trapping carbon within them

Question 8

What is crude oil and natural gas formed from?

Answer 8

Formed from deposits of plankton

Question 9

What is coal, and what is it formed from?

Answer 9

It is a sedimentary rock and is formed from thick plant deposits

Question 10

What is limestone and what is it formed from?

Answer 10

It is a sedimentary rock and is mostly made of calcium carbonate deposits from the shells and skeletons of marine organisms.

Question 11

How did marine animals form their skeletons?

Answer 11

Their shells and skeletons were formed from the carbonates on the seabed

Question 12

When did algae evolve?

Answer 12

2.7 billion years ago when it first produced oxygen

Question 13

How did oxygen levels in the atmosphere increase?

Answer 13

When green plants and algae stated photosynthesising - decreasing CO2 and increasing O2

Question 14

What happened due to increase in oxygen levels in the atmosphere?

Answer 14

More complex life like animals could evolve

Question 15

When did the atmosphere reach a composition similar to how it is today?

Answer 15

About 200 million years ago

Question 16

What is the composition of the atmosphere like currently?

Answer 16

approx. 80% nitrogen, 20% oxygen and less than 1% other gases (mainly carbon dioxide, noble gases and water vapour

Question 17

How is the Earth able to support life?

Answer 17

Greenhouse gases act as an insulating layer in the Earth’s atmosphere.

Question 18

What is true of all particles concerning radiation?

Answer 18

All particles absorb certain frequencies of radiation

Question 19

What type of radiation do greenhouse gases absorb?

Answer 19

The absorb long wavelength radiation - thermal radiation - that reflect back off the surface of the earth.

Question 20

Explain the greenhouse effect

Answer 20

Greenhouse gases act as an insulating layer in the Earth’s atmosphere
They absorb thermal radiation that is reflected back off the Earth.
The particles re-radiate it in all directions, including back towards the earth.
The thermal radiation trapped in the atmosphere results in the warming of the surface of the Earth
This is known as the greenhouse effect.

Question 21

List the human activities that affect the amount of greenhouse gases in the atmosphere

Answer 21

Deforestation, burning fossil fuels, agriculture and creating waste

Question 22

Describe deforestation’s impact on the greenhouse effect

Answer 22

Fewer trees means less CO2 is removed from the atmosphere via photosynthesis

Question 23

Describe how burning fossil fuels increases greenhouse gases in the atmosphere

Answer 23

Carbon that was locked up in these fuels is released as CO2

Question 24

Describe how agriculture impacts the amount of greenhouse gases in the atmosphere

Answer 24

More farm animals produce more methane through their digestive processes

Question 25

How does creating waste negatively impact the Earth's atmospheric composition?

Answer 25

More landfill sites and more waste from agriculture means more CO2 and methane released by decomposition

Question 26

Describe briefly 4 consequences of climate change?

Answer 26

- Increase in global temperature may cause ice caps to melt, increasing sea levels and risk of flooding - Changes in rainfall patterns causes varied distribution, meaning regions may have too much or too little water to produce food - Frequency and intensity of storms may also increase - Changes in temp may affect wild species and change their distribution

Question 27

What is a carbon footprint?

Answer 27

They are a measure of the amount of carbon dioxide and other greenhouse gases released over the full life cycle of something.

Question 28

Why is is hard to measure the carbon footprint of something?

Answer 28

There are many different factors to consider, e.g. carbon emissions of manufacturing, usage, disposal

Question 29

Why do people measure the carbon footprints of different things?

Answer 29

Gives us an idea of the objects that are the worst emitters, and helps us find what we need to get alternatives for, or altogether avoid.

Question 30

How can we reduce carbon footprints?

Answer 30

Using renewable energy Using more efficient processes Governments could tax individuals and corporation based on their emission of greenhouse gases Governments can cap emissions and sell licences for emissions up to that cap Using carbon capture technology

Question 31

How does using more efficient processes help with reducing carbon footprints?

Answer 31

They conserve energy and cut down on waste, which in turn reduces methane emissions

Question 32

How does carbon capture technology work?

Answer 32

It captures the CO2 produced by burning fossil fuels before it's released into the atmosphere, which can then be stored deep underground in cracks in the rock, such as old oil wells

Question 33

Why are technologies for carbon emissions not used more?

Answer 33

Carbon capture and storage is a relatively new idea, still at the developmental stage Renewable energy technologies like solar panels are still quite expensive

Question 34

Why are governments hesitant to tax and cap emissions?

Answer 34

It might affect economic growth, and international agreements are hard to make when it concerns economic sacrifice

Question 35

List ways an individual can decrease their carbon footprint

Answer 35

- choosing to walk or cycle instead of using a car - reducing use of air travel - saving energy at home

Question 36

What do fossil fuels contain that combust?

Answer 36

Hydrocarbons The carbon and hydrogen are oxidised, meaning carbon dioxide and water vapour are released back into the atmosphere.

Question 37

What type of combustion happens under enough oxygen and not enough oxygen?

Answer 37

Complete and incomplete combustion

Question 38

What happens in complete combustion?

Answer 38

All of the fuel burns completely, as there is plenty of oxygen to oxidise it

Question 39

What happens in incomplete combustion?

Answer 39

When there's not enough oxygen, not all of the fuel burns. Under these conditions, particulates and unburned hydrocarbons are released. Carbon monoxide, water and carbon dioxide can also be produced

Question 40

What are particulates?

Answer 40

Solid particles made of carbon, known as soot

Question 41

Explain the problems that particulates can cause

Answer 41

If particulates are inhaled, they cause respiratory problems as they get stuck in the lungs and cause damage They form clouds (smog) that reflect sunlight back into space, meaning less light reaches earth, known as global dimming

Question 42

How does carbon monoxide harm humans?

Answer 42

It is a toxic gas that binds to the haemoglobin in your blood, so less oxygen can be transported around the body. This can lead to fainting, a coma or even death

Question 43

Why is carbon monoxide hard to detect?

Answer 43

Colourless and odourless

Question 44

When is sulfur dioxide released?

Answer 44

During the combustion of fossil fuels that contain sulfur impurities. The sulfur in the fuel oxidises

Question 45

How and when are nitrogen oxides formed?

Answer 45

They are caused by the reaction of nitrogen and oxygen in the air. This requires very high temperatures, so can happen in internal combustion engines of cars

Question 46

How is acid rain formed?

Answer 46

When sulfur dioxide and nitrogen oxides mix with water in clouds, they form dilute sulfuric and dilute nitric acid., which then falls as acid rain

Question 47

What is the damage caused by acid rain?

Answer 47

Kills plants, damages buildings and statues, also corrodes metal

Question 48

How are sulfur dioxide and nitrogen oxides bad for human health?

Answer 48

Cause respiratory issues

Question 49

Why is evidence for the early atmosphere limited?

Answer 49

Large time scale of 4.6 billion years

Question 50

What leads to simplified models of climate change in the media?

Answer 50

It is difficult to model such complex systems as global climate change. This leads to simplified models, speculation and opinions presented in the media that may be based on only parts of the evidence and which may be biased.