The Atmosphere

Question 1

What were the gases of the early atmosphere?

Answer 1

Mostly Water vapour
Carbon dioxide
Nitrogen
Other gases

Question 2

Describe how the present day atmosphere evolved 🌊🤍

Answer 2

1.mostly water vapour, lots of volcanic activity
2.mostly carbon dioxide, earth cooled down and water vapour condenses to form oceans
3.increased in oxygen, decreased in CO2, evolution of photosynthesising plants and algae
4.mostly nitrogen and oxygen, evolution of photosynthesising and respiring plants and animals

Question 3

Composition of modern day gases in the atmosphere

Answer 3

Nitrogen-78
Oxygen-21
Argon-0.9
Carbon dioxide-0.04

Question 4

Properties and uses of 6 gases in the air

Answer 4

Nitrogen- plant nutrient, fertiliser
CO2- starves fire of O2, fire extinguisher
O2- respiration reactant, life support, medical uses
Argon- inert, fill lightbulbs
Neon- glows, advertisement signs
Helium- less dense than air, helium balloons

Question 5

What is fractional distillation?

Answer 5

A method of separating liquids according to their different boiling points

Question 6

Fractional distillation method:

Answer 6

1. Cool air down to -200°C, CO2 is solid at this point and can be easily removed
2. Pass liquid air into fractionating column
3. Warm at bottom, cool at top
4. Oxygen boiling point-183°C, Nitrogen boiling point-196°C
5. Oxygen becomes liquid, collected at bottom
6. Nitrogen remains gas, rises to be collected at top