CHEMISTRY OF THE ATMOSPHERE Flashcards
(39 cards)
What is the current composition of the Earth’s atmosphere?
About 80% nitrogen and 20% oxygen, with other gases making up less than 1%.
Other gases include carbon dioxide, water vapor, and noble gases.
What role did volcanic activity play in the early atmosphere of Earth?
Produced large amounts of carbon dioxide, water vapor, nitrogen, methane, and ammonia.
The early atmosphere was mostly carbon dioxide, similar to Mars and Venus today.
What significant change occurred about 2.7 billion years ago?
The appearance of algae, followed by the evolution of green plants.
Both groups are capable of photosynthesis.
What process do algae and green plants use to alter atmospheric composition?
Photosynthesis, which takes in carbon dioxide and produces oxygen.
This process has led to a decline in atmospheric carbon dioxide and an increase in oxygen levels.
What happened to the carbon from dead algae and plants?
They sank to the seabed and became buried in sediment, forming sedimentary rock, oil, and gas.
This process traps carbon and prevents it from re-entering the atmosphere.
What types of fossil fuels are formed from dead marine organisms?
Crude oil and natural gas, primarily from dead plankton.
Plankton are tiny organisms that float in the ocean.
What sedimentary rock is primarily made from dead plant material?
Coal.
Coal is formed from thick deposits of plant material over millions of years.
What is limestone primarily composed of?
Calcium carbonate from marine organisms’ shells and skeletons.
Limestone is also a type of sedimentary rock.
True or False: The theory of atmospheric evolution is fully proven.
False.
It remains a theory supported by evidence but not without uncertainties.
Fill in the blank: The early Earth’s atmosphere was mostly composed of _______.
[carbon dioxide].
What was the effect of photosynthesis on the evolution of complex life?
Allowed more complex life forms, like animals, to evolve due to increased oxygen levels.
The gradual increase in oxygen was crucial for the development of aerobic organisms.
In the first billion years, the gases that formed Earth’s early atmosphere came mainly from which source?
volcanic activity
During the first billion years, which two gases were released from volcanoes?
water vapour
carbon dioxide
What is the difference between global warming and climate change?
Global warming refers specifically to the increase in Earth’s average temperature, while climate change encompasses all the effects of global warming on the climate, including changes in weather patterns.
What role does the atmosphere play in regulating Earth’s temperature?
The atmosphere acts like an insulating blanket or greenhouse, keeping in the perfect amount of the sun’s heat energy to maintain a stable temperature on Earth.
What type of radiation does the sun emit that reaches Earth?
Short wavelength radiation.
What happens to the sun’s heat energy after it hits the Earth’s surface?
Some energy is absorbed and heats the ground, while most is re-emitted or reflected back into the atmosphere as longer wavelength radiation.
How do greenhouse gases contribute to the greenhouse effect?
Greenhouse gases absorb heat energy and re-emit it in random directions, keeping heat close to Earth and warming the atmosphere.
What are the two main reasons for the rising levels of carbon dioxide in the atmosphere?
- Burning fossil fuels
- Deforestation
What are the two main sources of methane emissions?
- Digestion in farm animals
- Decomposition of organic waste
True or False: The steady increase in Earth’s temperature can be observed through historical records.
True
What does climate change refer to?
Climate change refers to all of the effects of global warming on long-term weather patterns across the planet.
What are some consequences of global warming on weather events?
Rare weather events like droughts, hurricanes, and floods will become both more common and more severe.
