Chemistry of the atmosphere

How much does each gas make up of the atmosphere

• nitrogen→ 78%

• Oxygen → 21%

• Other gases → 1%

How did the earths atmosphere become what it is today

• Scientists believe earth formed 4.5 billion years ago as a ball of molten rock and minerals

• Volcanoes released CO2, water vapour and nitrogen into the atmosphere along with smaller amounts of methane and ammonia

  → means the early atmosphere was mainly CO2

• Water vapour condensed into liquid water and fell as rain, it formed the oceans and gases dissolved in them

• CO2 dissolves in the oceans where it was locked up as calcium carbonate and led to formation of sediments in sea bed

• Evolution of algae which photosynthesised causing a rise in oxygen (released through photosynthesis) and decrease in CO2 as more plants grew

• More complex plant life then animals who used O2 for respiration

• Over time living organisms removed most of CO2 from atmosphere and so,e of this was locked up in fossil fuels

What is the earths atmosphere made out of

• elements

• Compounds

• Mixtures

What is an element

A substance made up of only one type of atom

What is a compound

A substance made up of 2or more different types of atoms chemically bonded together

What is a mixture

2 or more different particles that are not chemically bonded together

What’s NH3

• ammonia

• Compound

What’s CH4

• methane

• Compound

What’s H2O

• water

• Compound

Why was argon discovered much later than the other gases in our atmosphere

Very unreactive so hard to test for. It’s a Nobel gas and has a full outer shell

What chemical reactions effect the levels in dioxide and oxygen in the atmosphere

• carbon dioxide dissolved in the ocean

• Algae evolved and photosynthesised

Why have CO2 levels increased over the past hundreds of years

• deforestation

• Increase in burning of fossil fuels

• Industrial Revolution.

What is the process of global warming

• the sun radiates shorter wavelengths of (UV vis) waves through the atmosphere to the earths surface

• It gets absorbed and re emitted as heat (infra red) which are longer waves → these lengths if wavelengths are similar to CO2 and CH4 lengths

• The green house gases then absorb the infra red wave length so then the heat is trapped

• This causes a temperature increase

What are fossil fuels made of and what happens when they burn

• made of carbon and hydrogen so when they burn:

  • Carbon + Oxygen → carbon dioxide

  • Meghan + oxygen → carbon dioxide + water

What does global warming cause

And increase in temperature overall

What’s climate change

• effects of global warming

• Long term weather patterns

• Sea levels rising → increase in flooding

• Decrease in biodiversity and extinction

Starting from green house gases, how does this lead to climate change and what does climate change cause

• green house gases → global warming → climate change

• climate change leads to

  • sea levels rising

  • Extinction and loss of biodiversity

  • Extreme weather events and increase in droughts and flooding

  • Increase in spread of diseases → tropical diseases move further

What’s the main cause of pollutants in our atmosphere

Combustion

What do most fuels contain

Hydrocarbons

Which gases are released into the atmosphere when a fuel is burned

• carbon dioxide

• Carbon monoxide

• Suffer dioxide

• Nitrogen oxides

Carbon monoxide

• Produced by incomplete combustion of fossil fuels

• When inhaled carbon monoxide binds to red blood cells instead of oxygen, preventing them from transporting O2 around the body

• Hydrocarbon +oxygen → carbon monoxide + water

Sulfur dioxide

• Most fossil fuels contain sulfur

• Oxygen + sulfur → sulfur dioxide

• Can cause breathing problems in humans

• Can dissolve into rain water causing acid rain which damages leaves and roots

Nitrogen oxides

• Car and aeroplane engines take in air and the high temperature and pressure in the engine cause nitrogen + oxygen → nitrogen oxides

• Nitrogen oxides can cause breathing problems in humans

• Nitrogen oxides can dissolve into rain water and causes acid rain → acid rain damages trees leaves and roots (effects photosynthesis and absorption of minerals)

• Nitrogen. + oxygen can slo react and from nitrogen monoxides