chemistry c13 retrieval practice

love me some trip sci

List the names and chemical formulae of the main gases which scientists speculate were present in the earth's early atmosphere

• Carbon dioxide (CO₂)
• water vapour (H₂O)
• nitrogen (N₂)
  (with traces of methane, CH₄, and ammonia, NH₃)

Describe how water vapour was removed from the earth's early atmosphere

Water vapour in Earth's early atmosphere condensed and fell as rain as the planet cooled, forming oceans.

Describe 4 ways that carbon dioxide was removed from the earth's early atmosphere

• CO₂ dissolved in early oceans as they formed.
• CO₂ reacted with metal oxides to form carbonate rocks (e.g., limestone).
• Early plants and algae absorbed CO₂ to produce O₂.
• Over millions of years, dead plants and animals that absorbed CO₂ were buried and turned into fossil fuels.

Describe how oxygen was added to the earth's atmosphere.

As plants spread across the Earth, they photosynthesised, producing O₂, which built up in the atmosphere over time.

Describe how nitrogen was added to the earth's atmosphere

Nitrogen entered Earth's atmosphere from volcanic eruptions, which released nitrogen gas (N₂). Over time, nitrogen built up in the atmosphere because it is very unreactive.

List the 3 main gases in the earth's atmosphere today

-nitrogen (78%)
-oxygen (21%)
-argon (1%)

State the 3 main greenhouse gases and describe how they can be formed.

Carbon Dioxide (CO₂): Produced by burning fossil fuels, deforestation, and certain industrial processes.
Methane (CH₄): Emitted from livestock, landfills, decaying organic matter, and during the production and transport of fossil fuels.
Nitrous Oxide (N₂O): Released from the use of fertilisers, as well as from the burning of fossil fuels and industrial processes.

Describe the greenhouse effect

• Sunlight passes through Earth's atmosphere to the surface.
• Earth absorbs sunlight and radiates it back as heat.
• Some of the infrared heat escapes into space, but greenhouse gases (eg CO₂, CH₄, N₂O) trap much of it in the atmosphere.
• Trapped heat warms the Earth, making it habitable, but human activities are increasing greenhouse gases, leading to enhanced global warming.

Describe the benefits of the greenhouse effect

The greenhouse effect keeps Earth warm enough to support life and stable climates. Without it, the average temperature would be about -19°C, too cold for most life forms.

Describe the trend in carbon dioxide levels from 1960 to 2010

CO₂ levels in the atmosphere steadily increased each year, with a more rapid rise in recent decades.

Explain the trend in carbon dioxide levels from 1960 to 2010

This is because of increased fossil fuel consumption, deforestation, and industrial activities. It reflects the growing impact of human activities on the environment, causing global warming and climate change.

Explain what is meant by "climate change"

Long-term changes in temperature and weather patterns, mostly driven by human activities like burning fossil fuels.

Explain what is meant by "global warming"

The long-term increase in Earth's average temperature due to higher levels of greenhouse gases from human activities.

Describe how scientists gather evidence for the link between greenhouse gases and climate and how they can predict future climate change.

Scientists gather evidence by analysing ice cores from Greenland, which have trapped gases, to study past CO₂ levels and climate. This helps them understand the link between greenhouse gases and climate. They use computer models to predict future climate changes, though these predictions cannot be certain.

What is peer review and why is it important?

Peer review is when another scientist reviews your work for accuracy. It is important because it allows others in the field to assess a scientist's investigations and results.

Explain why information in a scientific journal would be more trustworthy than a newspaper article on the same topic?

• Experts review and validate the research.
• Journals include thorough methods and evidence.
  -Written by specialists in the field.
  -Focused on evidence-based findings, without being simplified/exaggerated

Describe 4 possible consequences of climate change

• Melting ice caps and glaciers cause sea levels to rise, leading to coastal flooding.
• Increased frequency and severity of storms, heatwaves, and heavy rainfall.
• Changes in habitats and migration patterns affect wildlife and plant species.
• Altered growing conditions and extreme weather can reduce crop yields and food supply.

What does carbon neutral mean?

Balancing emitted CO₂ with an equivalent amount removed/offset, resulting in no net increase in CO₂ emissions.

What are biofuels?

Fuels made from organic materials like plants and animal waste, used as an alternative to fossil fuels. Examples include ethanol and biodiesel.

What is a carbon footprint?

The total amount of CO₂ and other greenhouse gases emitted by an individual or organisation.

What is carbon capture and storage (CCS)?

Where CO₂ is collected from industrial sources before it reaches the atmosphere, moved to storage sites via pipelines and is stored deep underground to prevent it from contributing to climate change.

How are nitrogen oxides formed?

Nitrogen and oxygen from the air react in the high temperature of an engine

How is sulphur dioxide formed?

Sulphur impurities in fossil fuels react with oxygen.

How is carbon dioxide formed?

complete combustion of fossil fuels

How is carbon monoxide formed?

Incomplete combustion of fossil fuels

How are particulates (smoke) formed?

Particulates are formed from incomplete combustion of fuels (especially diesel), industrial processes, and vehicle emissions.

Which air pollutants are formed directly or indirectly from burning fossil fuels?

Direct: CO₂, CO, NOx, Particulates
Indirect: Ozone (from NOx and volatile organic compounds in sunlight), Sulphur Dioxide

Describe 2 ways to reduce sulphur dioxide emissions from power stations

Install equipment to clean SO₂ from exhaust gases.
Use fuels with less sulfur.

Which 2 pollutants cause acid rain?

sulphur dioxide and nitrogen oxides

Describe how acid rain is formed

SO₂ and NOx are released from burning fossil fuels. These gases react with water vapor in the atmosphere to form sulfuric and nitric acids. The acids fall to Earth as acid rain.

Describe 3 problems caused by acid rain

-Ecosystem Damage: Harms soil and water bodies, disrupting plant and animal life.
-Building Corrosion: Erodes structures, especially limestone and marble.
-Water Quality Issues: Lowers pH in water bodies, affecting aquatic life.

What is smog?

a mixture of smoke, chemicals, and fog

Which 3 pollutants can combine to cause smog?

Nitrogen Oxides (NOx)
Volatile Organic Compounds (VOCs)
Particulates

How is smog harmful?

-Can cause respiratory problems, aggravate asthma, and lead to other health issues.
-Causes hazy conditions that decrease visibility on roads.
-Affects plants, animals, and can harm ecosystems.

What is global dimming?

Where particulates made from combustion cover the atmosphere, reflecting sunlight so less light reaches the surface.

How can particulates be harmful to health?

-cause global dimming
-damage lung cells
-cause cancer

How can carbon monoxide be harmful to health?

-CO binds to haemoglobin more effectively than O₂, reducing oxygen transport in the blood.

• Exposure can cause headaches, dizziness, confusion, and fatigue.
• High levels/prolonged exposure can lead to severe health issues, eg brain damage/death.

How can nitrogen oxides be harmful to health?

-Increased sensitivity to respiratory infections and allergies
-Can irritate the respiratory system, causing coughing, wheezing, and shortness of breath.

• NOₓ exposure can worsen asthma and other respiratory conditions.
• Long-term exposure may reduce lung function

How can sulphur dioxide be harmful to health?

-Irritation of the throat and eyes
-Can irritate the respiratory system, causing coughing and shortness of breath.
-SO₂ exposure can worsen asthma and other chronic respiratory conditions.
-Long-term exposure may lead to reduced lung function

Which pollutant causes global dimming?

particulates