Atmosphere Flashcards
What is the approximate proportion of nitrogen in Earth’s current atmopshere?
80%
What is the approximate proportion of oxygen in Earth’s current atmopshere?
20%
There are small proportions of water vapour, noble gases and which other gas in Earth’s current atmosphere?
carbon dioxide
When Earth was formed it’s atmosphere was similar to which planets?
Venus and Mars
Earth’s early atmosphere was similar to Venus and Mars, what do their atmosphere’s consist of?
Carbon dioxide with little or no oxygen
What produced the gases present in Earth’s early atmosphere?
Volcanoes
Which gases were present in Earth’s early atmosphere?
Carbon dioxide water vapour and nitrogen with small amounts of methane and ammonia
Why have theories about Earth’s early atmosphere developed and changed over time?
Evidence is limited
By what process do algae and plants produce oxygen?
Photosynthesis
Write the word equation to represent photosynthesis
carbon dioxide + water gives oxygen + glucose
How did the world’s oceans form?
The Earth’s temperature cooled, causing water vapour in the air to condense
How did the oceans reduce atmospheric levels of carbon dioxide in Earth’s early atmosphere?
Carbon dioxide dissolved in the oceans
How did algae and plants reduce levels of carbon dioxide in Earth’s early atmosphere?
By photosynthesising
What was formed when shells of organisms made using dissolved carbon dioxide, fell to the bottom of the ocean and were covered and compressed
Sedimentary rock
What was formed when plants that grew millions of years ago, died and were trapped and compressed under rocks
Coal
