1. Weathering and Erosion
Science 4th grade
Ms. Maldonado

2. What is Weathering? Weathering is the process of breaking down rocks
Two forms of weathering:
Mechanical
Chemical

3. Chemical Weathering
Chemical weathering occurs when minerals are chemically changed causing them to dissolve or change to another mineral
Oxidation
Acid
Water

4. What is Mechanical Weathering?
Mechanical weathering is breaking down by natural or physical processes
Ice
Animals
Plant Growth

5. Biological Weathering
It is the disintegration (breakdown) of rock by plants, animals and microbes. Growing plant roots can apply stress or pressure on rock. ... Microbial activity breaks down rock minerals by changing the rock's chemical composition. For example, rabbits and other burrowing animals can burrow into a crack in a rock, making it bigger and splitting the rock.

6. Delta
A Delta is a landform that forms from deposition of sediment carried by a river as the flow leaves its mouth and enters slower-moving or standing water.

7. Delta
 It is a piece of land in the shape of a triangle or fan made by deposits of mud and sand at the mouth of a river.

8. Sediment
1 : the material from a liquid that settles to the bottom. 2 : material (as stones and sand) carried onto land or into water by water, wind, or a glacier.

9. Oxidation
When iron reacts with oxygen it forms a chemical called rust.

10. Acid Rain
Acid rain is rain that has been made acidic by certain pollutants in the air. Acid rain is a type of acid deposition, which can appear in many forms. Wet deposition is rain, sleet, snow, or fog that has become more acidic than normal.

11. Acid Rain

12. Deposition
Erosion is when materials like soil and rocks, are moved by wind or water. All these materials are called sediments. Erosion and deposition are constantly happening. Deposition is when those sediments are deposited, or dropped off, in a different location. These processes change the way the surface of the earth looks over time

13. Decompose
Decompose is defined as to rot, to decay, to break down into parts or to disintegrate into the earth, or to cause something to break down or rot.

14. Abrasion
Abrasion is a process of erosion which can happen in four different ways. The first type of abrasion is caused by ice or glaciation. ... As waves break on the shore, the water, stones and the energy of the waves cause erosion.

15. Abrasion
The second type of abrasion is caused by rivers. Flowing water hits the channel walls and causes erosion. Pebbles or stones in the river also cause erosion when they hit the channel walls

16. Abrasion
The third type of abrasion is through the action of waves. As waves break on the shore, the water, stones and the energy of the waves cause erosion.

17. Abrasion
The final type of abrasion is caused by wind. The wind can transport sand and small stones, blowing them strongly against rocks and land. 

18. Glaciers
A glacier is a large area of thick ice that remains frozen from one year to the next. Glaciers also slowly flow over the land.

19. Organic Material
It is matter that has come from a recently living organism. It is capable of decay, or is the product of decay; or is composed of organic compounds.

20. Evaporation
Evaporation: Evaporation is when the sun heats up water in rivers or lakes or the ocean and turns it into vapor or steam. The water vapor or steam leaves the river, lake or ocean and goes into the air. ... Water vapor in the air gets cold and changes back into liquid, forming clouds. Evaporation: Evaporation is when the sun heats up water in rivers or lakes or the ocean and turns it into vapor or steam. The water vapor or steam leaves the river, lake or ocean and goes into the air. ... Water vapor in the air gets cold and changes back into liquid, forming clouds.

21. Evaporation

22. Condensation
Condensation is the process by which water vapor in the air is changed into liquid water. In other words, the water in the air, a gas known as water vapor, from your hot shower cooled when it met the surface of the cold mirror. This caused the water vapor to condense, or turn into its liquid form.