Topic C9 - chemistery of the atmosphere

Question 1

Describe the proportions of gases in the modern atmosphere

Answer 1

nitrogen - 78%
Oxygen - 21%
carbon dioxide - 0.04%

Question 2

how did the atmosphere evolve

Answer 2

Phase 1 - volcanic activity

at the start the surface was covered in volcanoes which erupted and released lots of gases which created the early atmosphere

mostly carbon dioxide with no oxygen

Volcanic activity also released nitrogen, which built up over time, as well as water vapour and small amounts of methane and ammonia

Phase 2 - Absorption of carbon dioxide

when water vapour condensed, it formed the oceans

carbon dioxide was removed as it was dissolved in the oceans. The dissolved CO2 want through reactions to form carbonate precipitates that formed sediments on the seabed

green plants and algae evolved and absorbed CO2 so they can carry out photosynthesis. later marine animals evolved. their shells and skeletons contained carbonates from the oceans

Phase 3 - produced oxygen

by photosynthesis

Question 3

what are some form of human activity that affect greenhouse gases

Answer 3

deforestation

Agriculture

creating waste

Question 4

what are some consequences of climate change

Answer 4

an increase in global temperature

change in rainfall patterns

change in temperature

Question 5

how can people reduce there carbon footprints

Answer 5

renewable energy sources or nuclear energy

more effective processes could conserve energy and cut waste

government could tax companies or individuals who emit large amounts of green house gases

governments should be able to a cap on the amounts of green house gases companies are allowed to release

Question 6

why is it hard to reduce greenhouse gasses

Answer 6

sill a lot of work to be down to be down to get alternative technologies that result in lower CO2 emissions

governments are worried making changes would impact on ecumenical growth of communities

hard to get international agreements to reduce emissions

have to get people change there lifestyle

Question 7

what problems can particulates have from the air

Answer 7

they can be inhaled and get stuck in the lunges and lead to respiratory problems

bad for the environment- they themselves or the clouds they help to produce , reflect light back to space . this means that less light reaches the earth- global dimming