Year 8 Earth and Rocks

Question 1

What are the layers of the Earth?

Answer 1

Crust, upper mantle, lower mantle, outer core, inner core

Question 2

How can we tell that continental drift is real?

Answer 2

There are similar fossils in countries far apart from each other

Question 3

How are igneous rocks formed?

Answer 3

They are formed from magma (molten rock) which has been erupted out of a volcano and cooled to solidify again

Question 4

What is intrusive magma?

Answer 4

Rocks formed inside a volcano. It has a large crystal size because it has cooled slowly

Question 5

What is extrusive magma?

Answer 5

Rocks formed outside a volcano. It has a small crystal size because it has cooled quickly

Question 6

How are metamorphic rocks formed?

Answer 6

When extreme heat and pressure is put on sedimentary and igneous rock

Question 7

How are sedimentary rocks formed?

Answer 7

When erosion breaks up rocks and weathering moves the bits away, and the grains are fixed together by compaction and cementation

Question 8

What are the three types of rock?

Answer 8

Igneous, sedimentary and metamorphic

Question 9

Give two examples of igneous rock

Answer 9

Granite and basalt

Question 10

Give two examples of sedimentary rock

Answer 10

Limestone and chalk

Question 11

Give two examples of metamorphic rock

Answer 11

Marble and slate

Question 12

What is the rock cycle?

Answer 12

1. Magma leaves volcano as lava and forms igneous rock
2. Transportation and deposition move the rock, and other layers are compacted onto it, forming sedimentary rock
3. Heat and pressure are put on the sedimentary rock and turn it into metamorphic rock
4. The metamorphic rock is moved underground by plates moving and melts into magma