Chapter 8 - The Earth and it's Rocks

Question 1

The crust

Answer 1

30 - 50 km thick under continents
7km thick under oceans

Question 2

Mantle

Answer 2

• Under crust
• 2900 km thick
• upper layer is called the asthenosphere

Question 3

The Core

Answer 3

• dense
• iron and nickle
• Outercore : liquid
• Innercore : Solid

Question 4

Weathering

Answer 4

Breaking or dissolving of rocks

Question 5

Physical Weathering: Temperature change

Answer 5

Expand when heated, contract when cooled. Repeated expansion causes rocks to crack

Question 6

Physical Weathering:
Water and Ice

Answer 6

Rivers flow making a V shape, and glaciers leave behind a U shape.

Question 7

Physical Weathering:
Crystallization of Salts

Answer 7

Salt water can get in-between rocks and they evaporate, leaving salt crystals behind and expands, causing rocks to split and crack.

Question 8

Chemical Weathering

Answer 8

A chemical reaction between rocks and substances in the soil or air. Can lead to crumbling or color change.

Question 9

Biological Weathering

Answer 9

Breaking down of rocks by living organisms or their products. Can be physical or chemical.

Question 10

Erosion

Answer 10

Movement of weathered rock, e.g. wind or water

Question 11

Deposition

Answer 11

When weathered material carried by erosion is discarded somewhere.

Question 12

Meandering

Answer 12

When river slows down it bends, where material is deposited.