Gases in the atmosphere Flashcards
What are the 4 gases in the air? (4)
- Nitrogen
- Oxygen
- Argon
- Carbon dioxide
What the percentage of nitrogen in the air?
78.1
What the percentage of oxygen in the air?
20.9
What the percentage of argon in the air?
0.9
What the percentage of carbon dioxide in the air?
0.004
Calculating the quantity of oxygen in the atmosphere? (formula)
Final volume/Initial volume x100
Calculating the quantity of oxygen in the atmosphere? (experiment with copper) (3)
- 100 cm3 of air passed from side to side over copper that was being heated with a Bunsen burner
- Continue until the volume stops decreasing, then record the volume of remaining air
- There would be about 79cm3
left, showing that 21cm3 of the original 100cm3 of air was oxygen
What is combustion an example of?
Combustion is an example of oxidation
What happens in an oxidation reaction
a substance gains oxygen
Example of an oxidation reaction? (magnesium)
magnesium + oxygen -> magnesium oxide
2Mg + O2 –> 2MgO
Describe the formation of carbon dioxide from the thermal decomposition of metal carbonates
Metal carbonate –(heat)-> metal oxide + carbon dioxide
What is the greenhouse gas effect?
Greenhouse gas effect maintains temperatures on Earth high enough to support
life
Examples of Greenhouse gases?
water vapour, CO2 & CH4
Explanation of the greenhouse gas effect (4)
- Electromagnetic radiation at most wavelengths from the sun passes
through the Earth’s atmosphere - The Earth absorbs some radiation and thus warms up (essential for life on
Earth). But some heat is radiated from the Earth as infrared radiation. - Some of this IR radiation is absorbed by greenhouse gases in the
atmosphere - Atmosphere warms up leading to the greenhouse effect and global
warming
