Chemisty Of The Atmosphere (topic 9)

Question 1

Todays atmosphere:

Answer 1

78% NITROGEN
21% OXYGEN
0.9% ARGON
0.04% CARBON DIOXIDE

Question 2

What is phase one/ the beginning of our atmosphere?

Answer 2

VOLCANOS: frequent eruptions resulted in high amounts of CARBON DIOXIDE and small amounts of methane, nitrogen & ammonia . There was very LITTLE oxygen

Question 3

How did oceans form

Answer 3

Water vapour from volcanoes condensed & formed oceans

Question 4

How was carbon dioxide reduced in our earths atmosphere?

Answer 4

1) photosynthesis- carbon dioxide is one of the reactants for photosynthesis, plants & algae removed carbon dioxide via photosynthesis.
2) oceans- removed large amounts and dissolved carbon dioxide for carbonate precipitates.
3) marine animals- evolution of marine animals removed carbonates from the ocean

Question 5

How did oxygen build up and what did this cause?

Answer 5

Plants & algae (photosynthesis) produced oxygen and this lead to animals being able to evolve

Question 6

What is the greenhouse effect and what is its purpose?

Answer 6

The sun emits short wavelengths into our atmosphere, the Earth absorbs the short wavelengths but is unable to absorb the long wavelengths so its reflected. The reflected wavelengths get absorbed by greenhouse gases, the gases then reradiates this as heat energy back into the earths surface.

This increases the temperature of the earths surface and is used as an insulating layer so the earth stays warm enough to support life.

Question 7

What are the 3 greenhouse gases

Answer 7

1) CARBON DIOXIDE
2) METHANE
3) WATER VAPOUR

Question 8

What human activities increase the concentration of greenhouse gases?

Answer 8

1) burning fossils fuels- releases carbon dioxide
2) agriculture- farm animals release methane when they digest food
3) deforestation- photosynthesis decreases so carbon dioxide levels increase
4) landfills- decomposition of landfills releases methane