Chem k

Question 1

what are the gases in todays atmosphere? ( and the percentages)

Answer 1

21% oxygen
78% nitrogen
the atmosphere also contains small proportions of various other gases, including carbon dioxide, water vapour and noble gases

Question 2

what are the 3 greenhouse gases

Answer 2

carbon dioxide, water vapour and methane

Question 3

what is the greenhouse effect?

Answer 3

The greenhouse effect is a natural process that occurs when greenhouse gases in the atmosphere trap heat from the Sun, warming the Earth’s surface. This process is necessary for life on Earth, but an increase in greenhouse gas concentrations can lead to global warming and climate change.

Question 4

what human activities increase the amounts of greenhouse gases?

Answer 4

-deforestation
-methane from framing
-combustion of fossil fuels

Question 5

How has the atmosphere changed?

Answer 5

Many scientists believe the early atmosphere was made up of mainly carbon dioxide, water vapour and small amounts of methane, ammonia and nitrogen, released by volcanoes. There was little to no oxygen around this time. The early earth was hot, but as it cooled the water vapour in the atmosphere condensed forming oceans.
As the ocean formed, carbon dioxide dissolved into the ocean. The carbon dioxide formed carbonates and formed solids. This process reduced the amount of carbon dioxide in the air.

Question 6

Name some atmospheric pollutants?

Answer 6

The combustion of fuels is a major source of atmospheric pollutants. Ex: fuels like coal, carbon monoxide, sulfur dioxide, carbon dioxide and oxides of nitrogen

Question 7

what were the gases in early earth’s atmosphere? ( and the percentages)

Answer 7

95% carbon dioxide, 3% nitrogen and 0.05% oxygen

Question 8

How did oxygen increase on early earth?

Question 9

How did the amount of carbon dioxide go down?

Answer 9

• it was locked up in sedimentary rocks
• used in photosynthesis
• dissolved into oceans