BELL WORK 11/5

What carved this rock? (see picture)

WEATHERING

BRAIN POP- WEATHERING

• http://www.brainpop.com/science/weather/weathering/preview.weml

AGREE OR DISAGREE?

1. Weathering is the same as erosion.

2. Humans are the main cause of weathering.

3. Plants can break rocks into smaller pieces.

4. Air and water are present in soil.

5. Soil that is 1,000 years old is young soil.

6. Soil is the same in all locations.

WEATHERING

•The mechanical and chemical processes that change objects on Earth’s surface over time• Over thousands of years, weathering can break

rock into smaller and smaller pieces, such as sand, silt, and clay.

HOW CAN ROCKS BE BROKEN DOWN? MINI LAB

•How are rocks in a stream different from other rocks?

•Complete lab

•What do you think caused your rocks to change?

MECHANICAL WEATHERING

•When physical processes naturally break rocks into smaller pieces

•The chemical makeup of a rock stays the same

CAUSES OF MECHANICAL WEATHERING

•Thermal expansion

• Ice wedging

•Abrasion

•Plant growth

•Animal activity

CAUSES OF MECHANICAL WEATHERING SKIT

•Groups of 4

•5 minutes to come up with a skit that explains your cause

• Skit must be 1 minute or less

SURFACE AREA

•The amount of space on the outside of an object

• When something is broken into smaller pieces, it has a GREATER surface area.

• Calculate the surface area to volume ratio for both cubes in figure 1.

BELL WORK 11/6

Why is the surface area of a rock important?

CHEMICAL WEATHERING

•Changes the materials that are part of a rock into new materials

CHEMICAL WEATHERING

WATER

• Most substances dissolve in water.

• The small pieces mix with water to form a solution and are washed away from the rock.

ACIDS

• Acids increase the rate of chemical weathering

OXIDATION

• combines the element oxygen with other elements or molecules

• The product of oxidation is called an oxide

DEBATE- AIR VS. WATER

•Pairs of 2

•Pick a role to play a debate between water and air regarding which is a more powerful agent of chemical weather

•Why??

WHAT AFFECTS WEATHERING RATES?

•The environment helps determine the rate of weathering.

• Mechanical weathering occurs fastest in locations that have a lot of temperature changes.

• Chemical weathering is fastest in warm, wet places.

•The type of rock being weathered also affects the rate of weathering and determines what kinds of products result.

WEATHERING RATES LAB

SUMMARY• Weathering is the

mechanical and chemical processes that change things over time.

• Mechanical weathering does not change the identity of the materials that make up rocks. It breaks up rocks into smaller pieces.

SUMMARY• Chemical weathering is the

process that changes the minerals that are part of every rock into new materials. Oxidation and reaction with an acid are both examples of chemical weathering. D

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WHAT DO YOU THINK NOW?AGREE OR DISAGREE?1. Weathering is the same as erosion.

2. Humans are the main cause of weathering.

3. Plants can break rocks into smaller pieces.

4. Air and water are present in soil.

5. Soil that is 1,000 years old is young soil.

6. Soil is the same in all locations.