rocks and weathering

Question 1

physical weathering

Answer 1

-freeze thaw
-salt crystalisation
-pressure release dilation

Question 2

factors affecting freeze-thaw

Answer 2

-climate
-rock porosity
-cracks in rocks

Question 3

salt crystalisation

Answer 3

-causes decomposition of rocks by solutions of salt
-due to fluctuation of temperature and evaporation of water causing salt to be produced

Question 4

salt crystalisation process

Answer 4

-salt water enters the joints of the rocks and then evaporates away
-causes the salt crystals to be formed and exert a force on the rock

Question 5

biological weathering

Answer 5

-caused by vegetation roots growing into the joints and exerting pressure on the rock

Question 6

chemical weathering

Answer 6

-involves chemical change to the rock composition
-most effective under the soil
-water that percolates through the soil contains organic acids from soil and vegetation

Question 7

carbonation

Answer 7

-rain dissolves to create weak carbonic acid
-the acid then reacts with the calcium carbonate this forms calcium bicarbonate
-causes rock to dissolve away

Question 8

hydrolysis

Answer 8

breaking down complex molecules by the chemical addition of water

Question 9

hydration

Answer 9

-some mineral molecules absorb water molecules
-this causes them to expand
-rock fractures

Question 10

Van’t Hoffs law

Answer 10

explains deep regolith in humid tropical regions