Weathering

Question 1

How are small rocks formed

Answer 1

Small rocks were broken down from larger pieces like boulders and mountains

Question 2

What causes the earths surface to change?

Answer 2

Natural forces like the wind and rain

Question 3

What are the 3 types of weathering?

Answer 3

1. Physical
2. Chemical
3. Biological

Question 4

What is physical weathering?

Answer 4

The mechanical or physical breakdown of rock into smaller pieces (sediments), without a change in the minerals chemical composition.

Question 5

What is Exfoliation or onion skin weathering?

Answer 5

This is when the heat expands the out layer of the rock, and then at night the out layers contracts since it is cooler.
This mainly happens in the desert.
Over time this causes small pieces to flake off the rock

Question 6

What is the onion skin weathering story?

Answer 6

1. There was a rock
2. The sun came up
3. The rock got hot and got bigger
4. Then it was night
5. The rock got cold and smaller
6. This happened everyday for a long time
7. The rock began to crack and a layer of the rock falls off

Question 7

What is freeze thaw weathering?

Answer 7

1. When it rains water finds its way into a thin crack
2. On cold nights the temperature falls and the water freezes.
3. Ice expands by 9% and wedges the rock apart
4. In the daytime the water thaws and sinks deeper into the crack
5. After this has happened many times the crack widens until the rock is split in 2
6. Small rocks then fall down the side of the valley and a called scree

https://www.youtube.com/watch?v=cwVF33jOmG8

Question 8

What is abrasion?

Answer 8

When pieces of rock collide with each other due to transportation by wind. ice, water or gravity.

Question 9

What is weathering?

Answer 9

The physical and chemical breakdown of rocks near the surface.

Question 10

What is biological weathering?

Answer 10

Weathering caused by living things

Question 11

What is responsible for most biological weathering?

Answer 11

Plants are responsible for most biological weathering

Question 12

What are the 3 types of physical weathering?

Answer 12

1. Abrasion
2. Ice Wedging
3. Onion Skin Weathering

Question 13

How do plants cause biological weathering?

Answer 13

,1. Roots grow into weaknesses in the rock ansd as they grow cause these cracks to become larger
2. Lichens, algae, bacterial or mosses produce weak acids. They are all organisms which grows on rocks. It creates chemicals which erode at the rock as it grows

Question 14

How do animals cause biological weathering?

Answer 14

Animals construct burrows to shelter in. This breaks apart or undermines rock leading to weathering
Other animals bore into rocks for protection either by scraping away grains or secreting acid to dissolve rock

Question 15

What is chemical weathering?

Answer 15

The process by which chemicals breakdown rock through a change in the mineral composition,
This happens fastest in a hot, moist climate

Question 16

What are the 3 types of chemical weathering?

Answer 16

1. oxidation
2. Dissolving
3. hydrolysis

Question 17

What is oxidation?

Answer 17

This occurs when oxygen from the air combines with iron rich minerals of the rock and this causes RUST

Question 18

What is acidic rain?

Answer 18

Carbon dioxide from the atmosphere combines with the water to make the rain water slightly acidic

Question 19

What is dissolving?

Answer 19

When the acidic rain falls on certain types of rock (limestone and marble) there is a chemical reaction which causes the rock to dissolve.

Question 20

What is Hydrolysis?

Answer 20

Wter combines with minerals such as mica and feldspar found in granite, to form clay.
The rock weakens and crumbles apart