structure of the earth

Question 1

what are the four layers of the earth?

Answer 1

inner core
outer core
mantle
crust

Question 2

what are tectonic plates “floating” on?

Answer 2

semi-molten layer of rock in the mantle

Question 3

what causes the plates to move?

Answer 3

convection currents within the mantle

Question 4

what is continental crust?

Answer 4

forms land
low density
30-50km thick

Question 5

what is oceanic crust?

Answer 5

forms under sea
dense
6-8km thick

Question 6

what causes convection currents?

Answer 6

1. heat from the core causes them in the mantle where heated rock rises towards the crust
2. causes the plates to move constantly