2.2 WHAT ARE ROCKS AND HOW ARE THEY A NATURAL RESOURCE?

Question 1

What are rocks?

Answer 1

Natural material made up of mineral grains

Question 2

Igneous rocks

Answer 2

Formed from molten rocks
E.g. Basalt, granite

Question 3

Sedimentary rocks

Answer 3

Formed under the sea
E.g. Chalk, limestone, sandstone, coal

Question 4

Metamorphic rocks

Answer 4

Formed when igneous and sedimentary rocks are exposed to high temperature and pressures
E.g. Marble, slate

Question 5

What is weathering?

Answer 5

Air, water, changing temperatures, plants and animals all attack rocks causing them to break down and rot away

Question 6

Freeze-thaw weathering

Answer 6

1. Water gets into a crack in a rock and freezes
2. As the water turns into ice - expands and causes the crack to widen
3. Repeated process - rock eventually splits into pieces

Question 7

Chemical weathering

Answer 7

1. Rainwater (slightly acidic) comes into contact with rock
2. Acid attacks the rock, causing it to rot and crumble

Question 8

Biological weathering

Answer 8

1. Plants and animals break down rock
2. Roots of plants and trees can get into cracks in rocks, causing them to split
3. Burrowing animals and worms can also weaken rocks