Early Atmosphere

Question 1

How is CO2 locked into the oceans

Answer 1

CO2 dissolves in the water, making insoluble carbonate compounds (sediment) after it reacted eg with metal oxides

Question 2

Where did the CO2 go?

Answer 2

Locked into oceans
Taken by plants (photosynthesis)

Question 3

Where did the carbon in the glucose end up?

Answer 3

New plant material

Question 4

How does the carbon in the glucose end up in animals?

Answer 4

Animals eat the plants

Question 5

What happened to the marine organisms?

Answer 5

Skeleton and shells covered by layers of sediment, forming sedimentary carbonate rocks due to heat and pressure.

Question 6

What happened to the remains of ancient organisms?

Answer 6

Crush’s by large scale movements of the earth, heated, formed fossil fuels

Question 7

How is crude oil/natural gas formed

Answer 7

Organisms covered by sediments, become layers of rock when compressed over millions of years

Question 8

How was coal formed

Answer 8

Buried
Absence of oxygen
Compressed over millions of years

Question 9

What is peer review

Answer 9

Research that is peer reviewed has been evaluated by other scientists who are experts in that area of science.

Question 10

Why aren’t scientists sure what happened

Answer 10

Lack of evidence

Question 11

Describe the % levels of different gases from the early atmosphere of the earth compared to now

Answer 11

Early:
5% N2, O2, Ar
95% CO2

Today:
78% N2
20.9% O2
0.9% Ar
0.03% CO2

Question 12

Name the 5 ways carbon is locked up in the earth

Answer 12

Limestone
Oceans
Rainforests
Fossil fuels
Living things

Question 13

How to find the relative formula mass (Mr)

Answer 13

Use the periodic table to find the relative atomic mass (Ar) of each element in the compound.
Multiply the atomic mass by the number of atoms of that element in the formula.
Add up all the values.
Eg. Finding the relative formula mass of CO2
Carbon: relative atomic mass of 12
Oxygen: relative atomic mass of 16
(12x1)+(16x2)=44

Question 14

Which one is the relative atomic mass number and which one is the proton number

Answer 14

The bigger, top number
The smaller, bottom number

Question 15

Summarise the stages of earths early atmosphere (1-6)

Answer 15

1. 4.6 billion years ago volcanoes released lots of CO2, methane gas, ammonia and water vapour into the atmosphere.
2. Earth cooled and water vapour condensed, forming oceans.
3. Plants and algae evolved and carried out photosynthesis.
4. Photosynthesis took CO2 out of the atmosphere and formed oxygen.
5. More and more CO2 was taken out eg when sedimentary rocks and crude oil formed
6. Today most of the atmosphere is mad sup of nitrogen and oxygen with very small amounts of other gases.

Question 16

What is mass extinction

Answer 16

When at least half of all species become extinct