Unit 9 - Atmospheric Chemistry Flashcards
What was the Earth’s early atmosphere like?
Likely composed of mainly carbon dioxide, with nitrogen and water vapour
Why are scientists not completely sure what the Earth’s early atmosphere was like?
It was so long ago so evidence supporting the claims is limited.
What landform covered the early Earth (and caused the gases to be emitted?)
Volcanoes
How were oceans formed?
Water vapour in the atmosphere (released by volcanic activity) condensed to form oceans.
How have levels of carbon dioxide decreased with time?
Carbon dioxide was dissolved into oceans, as well as being stored in sedimentary rocks. Algae and plants then evolved to photosynthesise, taking in carbon dioxide.
How have oxygen levels changed over time?
Photosynthesis by algae and green plants emit oxygen thus increasing levels
What is the greenhouse effect and how does it heat the Earth?
What keeps the Earth warm. Greenhouse gases (methane, carbon dioxide and water vapour) absorb long wavelength radiation reflected off the surface, increasing global temperatures.
What is carbon footprint?
measure of how much carbon dioxide is released into the atmosphere as a result of your actions
How is carbon monoxide produced?
Incomplete combustion due to a lack of oxygen in the fuel supply
What are the properties of carbon monoxide?
It is toxic to humans, colourless and odourless, making it very hard to detect.
Why is carbon monoxide toxic to humans?
It binds to the haemoglobin in red blood cells, reducing the oxygen they are able to transport around the body
What is a pollutant?
A substance with undesirable effects that is introduced to the environment.
What are particulates?
Microscopic particles suspended in the air that cause global dimming and health problems for humans
What causes acid rain and respiratory problems in humans?
Sulphur dioxide and oxides of nitrogen
Why are carbon particulates/soot dangerous?
They can cause health problems for humans and global dimming
