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16 Cards in this Set
- Front
- Back
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air is a mix of
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gases
suspended particles liquid or solid water |
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atoms
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smalles particle of an element existing alone or in a combination with other atoms
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molecules
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smallest particle of a substance, composed of one or more atoms
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water vapor
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– Added to air by evaporation, mostly from the oceans, and removed by precipitation
– Quantity: close to 0% over desert and polar regions to nearly 4% near tropics, most occurs within 5 km of surface which is where it evaporated from. |
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ozone (o3)
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varies spatially adn temporally
mostly found 20-40 km aloft humans introduce chlorofluorocarbons into atmosphere post wwii>which weakened the ozone layer |
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earth's earliest history
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earth formed 4.6 bya and acquired the moon by a collision
earth's early atmosphere: hydrogen adn helium |
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volcanic gases
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• Water vapor (70%): source of the oceans?
• CO2 (20%): huge! Where does it go? • Sulfur (9%) • Nitrogen, Argon, other gases including ammonia (NH3) and methane CH4(< 1%) |
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where did the oceans come from
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(1) water vapor from volcanoes condensed out and rained to the earth, forming oceans.
(2) Most water was brought to earth by asteroids in “late heavy bombardment” era from about 4.1 BYA to 3.8 BYA. |
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how did nitrogen sulfur and argon evolve in the atmosphere
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• Sulfur: becomes parts of rocks, not part of air
• Nitrogen: accumulates, it is little used geologically or by life forms on earth. Added by ammonia. Becomes 78% of air. • Argon: also accumulates, little used by life forms. Becomes 0.9% of air. |
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CO2
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– Was plentiful initially from vigorous volcanic activity
– Made the planet very warm in its early history |
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CO2 removal from the atmosphere (cools the planet) by the other “spheres”
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– Removed by rain falling from clouds
– Mixed into the growing oceans (hydrosphere), sea life with shells turn it into carbonate rock. – Stored in rocks on land (lithosphere). – Removed by expanding life forms (biosphere) through photosynthesis. |
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oxygen
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– Simple living organisms in the ocean started earth’s oxygen production.
– Free oxygen (not part of rocks, water or CO2) formed in noticeable abundance about 1.7 billion years ago, very slowly increases to current value of 21% |
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oxygen is created from oxygen
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When oxygen levels reached 2% it formed an ozone layer that protected earth’s surface. Life moves to land and plant life begins to flourish.
– Photosynthesis from plants then generated oxygen in large quantities. |
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what does co2 removal cause
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lowers temperatures, keeps them moderate
and generates rocks/minerals |
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what would happen to earth's oceans if they weren't a medium temperature
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too hot- would evaporate to space
too cold- they would freeze |
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how many fixed adn how many variable gases does
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atmospheric gases have 3 fixed and 3 variable gases
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