Chemisty The Atmosphere March 2019 Flashcards
What are the main gases in the atmosphere? How much is there of each?
Nitrogen - 78%
Oxygen - 21%
Argon - 0.9%
Other gases (mostly carbon) - 0.1%
What gases are likely to have been released by volcanoes in the early stages of Earth’s life?
Carbon dioxide, nitrogen, methane, ammonia and water vapour.
Where did oxygen come from?
It is thought that oxygen was formed by photosynthesis done by early life on Earth.
What happened to all the carbon dioxide?
It either dissolved into the oceans or was used in photosynthesis.
Dissolved - Insoluble compounds form sediment, soluble rocks are absorbed by animals which then die and become sediment. The sediment forms sedimentary rocks.
Photosynthesis - Plankton in oceans or plants in swamps photosynthesise and then decay under heat and pressure. Plankton forms crude oil and natural gas and the plants form coal.
What is a greenhouse gas?
A gas that absorbs long wave infrared radiation given off by the Earth but doesn’t absorb the Sun’s radiation.
What is global warming?
An increase in the temperature at the Earth’s surface.
What is peer-reviewing?
When scientific research is studied and commented on by experts in the same area of science to check that it is scientifically valid.
What does the term carbon neutral mean?
Fuels and process whose use results in zero net release of greenhouse gases to the atmosphere.
What are some methods for reducing the world’s carbon footprint?
- Increase in the use of alternative energy sources.
- Energy conservation (e.g. more efficient products).
- Carbon capture and storage.
- Carbon off-setting (e.g. planting more trees).
- Carbon taxes and licenses.
- Carbon neutral fuels such as ethanol.
What problems do the products of combustion cause?
Carbon dioxide - Greenhouse gas causing climate change and global warming.
Carbon monoxide - Toxic as it binds to haemoglobin in the blood causing it to carry less oxygen.
Soot (Carbon) - Can damage lungs as well as cause air pollution and blacken buildings.
Water vapour - No problems
Sulphur dioxide - Causes acid rain and respiratory problems for humans.
Nitrogen oxides - Causes acid rain and respiratory problems for humans.
Unburned hydrocarbons - Wastes fuel and are greenhouse gases.
What is water stress?
A shortage of fresh water.
What is a carbon footprint?
The amount of carbon dioxide and other greenhouse gases given out over the full service of a product, service or event.
