Chemistry 9.1.1

Question 1

The Proportion of Gases in the Air has not Changed much in ~___ Million Years.

Answer 1

200.

Question 2

Approximately how much of the Air is Nitrogen?

Answer 2

~4/5.

Question 3

Approximately how much of the Air is Oxygen?

Answer 3

~1/5.

Question 4

What other Gases are Present in the Air? (30

Answer 4

-Carbon Dioxide.

-Water Vapour.

-Trace Quantities of the Noble Gases.

Question 5

How can Scientists know the Composition of the Air from very long ago?

Answer 5

By Analysing the tiny Air Bubbles trapped in Ice Cores taken at the Poles.