The Atmosphere

Question 1

What percentage of the earths atmosphere is nitrogen ?

Answer 1

78%

Question 2

What is the percentage of the earths atmosphere that is oxygen ?

Answer 2

21 %

Question 3

What are the gasses in our atmosphere ?

Answer 3

Mainly Nitrogen and Oxygen aswell as other gassed such as carbon dioxide, water vapor and noble gases

Question 4

For how long have the gassed in our atmosphere stayed constant ?

Answer 4

Around 200 million years

Question 5

How old is the earth and why does this pose a problem.

Answer 5

4600 million years old meaning scientists cannot be certain about the early atmosphere

Question 6

What do scientist think happened in the first billion years ?

Answer 6

Intense volcanic activity
- realised the gasses that formed the atmosphere with one of these being water vapor also released large amounts of carbon dioxide
- as the earth cooled the water vapor condensed to from the oceans

Question 7

What did the early stage ( first billion years) of earths atmosphere what did it consist of?

Answer 7

Mainly carbon dioxide with little or no oxygen

Question 8

What was earths atmosphere during the early stages ( first billion years) similar to ?

Answer 8

Mars or Venus today

Question 9

What did the Volcanoes release apart from cater vapor and carbon dioxide ?

Answer 9

Methane and ammonia

Question 10

How was the early atmosphere different to the one of today ?

Answer 10

Early atmosphere was made up of mostly carbon dioxide but the modern day atmosphere contains a small amount of
Early atmosphere contained very little oxygen where as today 21% of the atmosphere is oxygen

Question 11

What happened to some of the carbon dioxide as the water vapor condensed to from the oceans ?

Answer 11

Dissolved in the oceans to form a weak acid which reacted with minerals in the sea to form precipitates

Question 12

What did the precipitates form over time ?

Answer 12

Sediments of carbonate rock on the sea bed

Question 13

What was some of the carbon dioxide in the sea used for ?

Answer 13

To make corals and shells of organisms such as mussles

Question 14

What is limestone ?

Answer 14

Sedimentary rock made of calcium carbonate of shells and skeletons

This caused the levels of carbon dioxide to fall

Question 15

When did algae first evolve and why is this important ?

Answer 15

2.7 billion years ago photosynthetic algae first evolved in the oceans
As photosynthesis produces oxygen which entered the atmosphere

Question 16

What happens after the evolution of algae ?

Answer 16

In the following billion years plants evolved which increased the levels of oxygen in the atmosphere which at some point allowed for animals to evolve

Question 17

How did carbon levels decrease ?

Answer 17

Formation of fossil fuels
Evolution of photosynthetic algae and plants

Question 18

What is sedimentary rock made out of and what does it contain ?

Answer 18

Made out of: dead algae and green plants and got buried In layers of sediment over millions of years it got compressed to form the rock
Contains: oil and gas which traps the carbon !