chemistry of the atmosphere

Question 1

What is the Earth’s atmosphere characterized as?

Answer 1

Dynamic and forever changing

Changes can be man-made or part of natural cycles

Question 2

What do scientists use to predict weather and climate change?

Answer 2

Complex software

Many variables influence weather and climate

Question 3

What are the primary components of the Earth’s atmosphere?

Answer 3

Approximately 80% nitrogen, approximately 20% oxygen, small proportions of carbon dioxide, water vapour, and noble gases

Proportions have remained stable for about 200 million years

Question 4

What was the likely composition of the Earth’s atmosphere during its early formation?

Answer 4

Mainly carbon dioxide with little or no oxygen gas

This resembles the current atmospheres of Mars and Venus

Question 5

What role did volcanic activity play in the formation of the early atmosphere?

Answer 5

Released gases that formed the early atmosphere and water vapour

Volcanic activity was intense during the first billion years

Question 6

What gases were produced by volcanoes that contributed to the early atmosphere?

Answer 6

Nitrogen, methane, and ammonia

Nitrogen gradually built up in the atmosphere

Question 7

What process occurred when the oceans formed that affected atmospheric carbon dioxide levels?

Answer 7

Carbon dioxide dissolved in water and carbonates were precipitated

This process reduced the amount of carbon dioxide in the atmosphere

Question 8

True or False: The composition of the atmosphere has changed significantly in the last 200 million years.

Answer 8

False

The proportions of gases have remained much the same

Question 9

Fill in the blank: The Earth’s atmosphere may have been similar to _______ and Venus today.

Answer 9

Mars

Early atmosphere likely consisted mainly of carbon dioxide

Question 10

What is a key challenge for scientists and engineers regarding air pollutants?

Answer 10

Developing solutions to reduce their impact

Increased levels of air pollutants pose significant problems

Question 11

What is the time scale for the evidence of the early atmosphere?

Answer 11

4.6 billion years

Evidence is limited due to this extensive time scale

Question 13

What is the equation representing photosynthesis?

Answer 13

6CO2 + 6H2O —> C6H12O6 + 6O2

Represents the conversion of carbon dioxide and water into glucose and oxygen.

Question 14

When did algae first produce oxygen?

Answer 14

About 2.7 billion years ago

This event marked the beginning of oxygen accumulation in the atmosphere.

Question 15

What process decreases carbon dioxide in the atmosphere?

Answer 15

Photosynthesis

Algae and plants utilize carbon dioxide to produce oxygen.

Question 16

What are two additional processes that decrease atmospheric carbon dioxide?

Answer 16

• Formation of sedimentary rocks
• Formation of fossil fuels

Both processes sequester carbon in different forms.

Question 17

How is limestone formed?

Answer 17

From calcium carbonate in the shells of sea creatures

When they die, their shells fall to the seabed and contribute to limestone formation.

Question 18

How are fossil fuels like coal, oil, and gas formed?

Answer 18

From buried plant and animal remains under high pressure and temperature

Chemical reactions convert carbon into fossil fuels over millions of years.

Question 19

What are greenhouse gases?

Answer 19

Gases that maintain temperatures on Earth high enough to support life

Includes water vapor, carbon dioxide, and methane.

Question 20

What is the greenhouse effect?

Answer 20

The process where the Earth’s surface absorbs short wavelength radiation and emits long wavelength radiation, which is absorbed by greenhouse gases

This process prevents heat from escaping into space, warming the atmosphere.

Question 21

Name two human activities that increase carbon dioxide levels in the atmosphere.

Answer 21

• Burning coal in power stations
• Burning petrol and diesel in cars

These activities release significant amounts of CO2.

Question 22

Name two human activities that increase methane levels in the atmosphere.

Answer 22

• Livestock farming (cows burping)
• Landfill sites

Both activities contribute to methane emissions.

Question 23

Fill in the blank: The main gases involved in the greenhouse effect are _______.

Answer 23

[water vapor, carbon dioxide, methane]

Question 24

True or False: The greenhouse effect is essential for maintaining life on Earth.

Answer 24

True

Without the greenhouse effect, Earth’s temperatures would be too low to support life.

Question 26

What is believed to cause the Earth's atmospheric temperature increase?

Answer 26

Human activities, specifically CO2 emissions ## Footnote Many scientists agree that human activities are responsible for the increase in atmospheric temperatures, leading to climate change.

Question 27

What challenges exist in modeling global climate change?

Answer 27

Complex systems lead to simplified models and biased media opinions ## Footnote The complexity of climate systems results in models that may oversimplify the evidence and lead to speculative conclusions.

Question 28

What should you be able to evaluate regarding reports on global climate change?

Answer 28

The quality of evidence ## Footnote Evaluating evidence quality is crucial for understanding climate change reports.

Question 29

What uncertainties exist in the evidence base for global warming?

Answer 29

Correlation vs causation and natural variations ## Footnote There is uncertainty about whether rising temperatures are due to human CO2 emissions or other factors like solar activity.

Question 30

What is a major cause of climate change related to temperature?

Answer 30

An increase in average global temperature ## Footnote The rise in global temperatures is a significant driver of climate change.

Question 31

List four potential effects of global climate change.

Answer 31

* Sea level rise due to evaporation of water * Desertification from reduced rainfall * Unusual weather patterns such as storms * Shortage of food due to crop failure ## Footnote These effects illustrate the far-reaching impact of climate change on the environment.

Question 32

What is the carbon footprint?

Answer 32

The total amount of CO2 and other greenhouse gases emitted over a product's life cycle ## Footnote Understanding the carbon footprint is essential for assessing environmental impact.

Question 33

How can the carbon footprint be reduced?

Answer 33

* Using less energy * Carbon capture and storage * Planting trees * Carbon neutral fuels ## Footnote These actions aim to minimize the emissions associated with various activities.

Question 34

What are some (5) reasons why actions to reduce emissions may be limited?

Answer 34

* Lack of belief in individual impact * Political disagreement * Incomplete international cooperation * Cost implications for industry * Potential hindrance to living standards in poorer countries ## Footnote These limitations highlight the complexity of addressing climate change on a global scale.

Question 35

True or False: Some scientists believe that changes in the Sun's energy output may contribute to temperature increases.

Answer 35

True ## Footnote There is debate among scientists regarding the causes of temperature changes, including solar activity.

Question 37

What is a major source of atmospheric pollutants?

Answer 37

The combustion of fuels ## Footnote Most fuels, including coal, contain carbon, hydrogen, and sometimes sulfur.

Question 38

What gases are released into the atmosphere when a fuel is burned?

Answer 38

Carbon dioxide, water vapour, carbon monoxide, sulfur dioxide, oxides of nitrogen ## Footnote Solid particles and unburned hydrocarbons may also be released.

Question 39

How is carbon monoxide produced by burning fuels?

Answer 39

By incomplete combustion when there isn't enough oxygen ## Footnote Incomplete combustion can produce carbon (particulates), carbon monoxide, and water.

Question 40

What are the products of complete combustion of a hydrocarbon?

Answer 40

Carbon dioxide and water ## Footnote The equation is: Fuel + oxygen → carbon dioxide + water.

Question 41

What is produced when sulfur in coal is burned?

Answer 41

Sulfur dioxide ## Footnote This occurs when sulfur reacts with oxygen.

Question 42

What causes the formation of nitrogen oxides?

Answer 42

Reaction of nitrogen and oxygen at high temperature in engines ## Footnote This reaction occurs during combustion processes.

Question 43

What are the properties of carbon monoxide?

Answer 43

Toxic, colorless, and odourless ## Footnote It is difficult to detect without specialized equipment.

Question 44

What health problems are associated with sulfur dioxide and oxides of nitrogen?

Answer 44

Respiratory problems and acid rain ## Footnote These pollutants can have significant environmental and health impacts.

Question 45

What effects do particulates have on the environment?

Answer 45

Global dimming and health problems for humans ## Footnote Particulates can block sunlight and contribute to various health issues.

Question 46

Fill in the blank: Incomplete combustion produces carbon __________ and carbon monoxide.

Answer 46

particulates

Question 47

True or False: Sulfur dioxide is produced by burning hydrogen.

Answer 47

False ## Footnote Sulfur dioxide is produced by burning sulfur.

Question 48

What should you be able to do regarding atmospheric pollutants?

Answer 48

Describe how carbon monoxide, soot, sulfur dioxide, and oxides of nitrogen are produced ## Footnote Also, predict the combustion products of a fuel based on its composition and conditions.