Our Changing Planet (core)

Question 1

Name the four layers of the earth

Answer 1

atmosphere, crust, mantle, core

Question 2

What causes tectonic plates to move?

Answer 2

convection currents in the mantle

Question 3

Why can’t scientists predict when and where earthquakes will happen?

Answer 3

they don’t know enough about what is happening inside the earth

Question 4

Why weren’t Wegener’s theories accepted for many years?

Answer 4

he couldn’t explain why the continents moved

Question 5

Where did the carbon dioxide, water vapour and nitrogen come from in the early atmosphere?

Answer 5

volcanoes

Question 6

What produced the oxygen in the atmosphere?

Answer 6

photosynthesis

Question 7

Why are we not sure about how life began?

Answer 7

not enough evidence

Question 8

In what ways did carbon from carbon dioxide get ‘locked up’?

Answer 8

in fossil fuels, in sedimentary rocks

Question 9

What are the approximate percentages of nitrogen and oxygen in the air?

Answer 9

78% 21%

Question 10

Why can gases in air be separated through fractional distillation?

Answer 10

they have different boiling points

Question 11

Name two processes that release carbon dioxide into the atmosphere

Answer 11

burning, respiration, decay

Question 12

Name two processes that remove carbon dioxide from the atmosphere

Answer 12

photosynthesis, dissolve into oceans

Question 13

Which human activity has been the main cause of the increase in carbon dioxide levels in the atmosphere?

Answer 13

burning fossil fuels