Lesson 1 Reading Guide - Vocab Weathering weathering mechanical weathering chemical weathering oxidation Lesson 1 Reading Guide - Vocab

Weathering and Its Effects The mechanical and chemical processes that change objects on Earth’s surface over time are called weathering. Over thousands of years, weathering can break rock into smaller and smaller pieces, such as sand, silt, and clay. Lesson 1-1

Mechanical Weathering When physical processes naturally break rocks into smaller pieces, mechanical weathering occurs. The chemical makeup of a rock stays the same during mechanical weathering. Mechanical weathering can be caused by ice wedging, abrasion, plants, and animals. Lesson 1-2

Lesson 1-2

Chemical Weathering Chemical weathering changes the materials that are part of a rock into new materials. These granite obelisks show how chemical weathering can affect some rock. Dr. Marli Miller/Getty Images Lesson 1-3

Chemical Weathering (cont.) Water is important in chemical weathering because most substances dissolve in water. The process of dissolving breaks up the minerals in the rock into small pieces. The small pieces mix with water to form a solution and are washed away from the rock. Acids are also agents of chemical weathering and cause more chemical weathering than pure water does. Lesson 1-3

Chemical Weathering (cont.) Oxidation combines the element oxygen with other elements or molecules. The product of oxidation is called an oxide. Lesson 1-3

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. Lesson 1-4

B. mechanical weathering C. oxidation D. ice wedging Which term refers to what happens when physical processes naturally break rocks into smaller pieces? A. chemical weathering B. mechanical weathering C. oxidation D. ice wedging Chapter Review – MC1

What is the product of oxidation? A. oxygen B. an oxide C. acid D. iron Chapter Review – MC2

Where does chemical weathering occur fastest? A. cool, dry places B. places with a lot of temperature changes C. warm, wet places D. none of these Chapter Review – MC3

A. mechanical weathering B. abrasion C. chemical weathering Which term refers to changes in the materials that are part of a rock into new materials? A. mechanical weathering B. abrasion C. chemical weathering D. ice wedging Chapter Review – STP1

Which of these can cause mechanical weathering? A. ice wedging B. abrasion C. plants D. all of the above Chapter Review – STP2

A. mechanical weathering B. oxidation C. chemical weathering Which of these occurs fastest in locations that have a lot of temperature changes? A. mechanical weathering B. oxidation C. chemical weathering D. none of these Chapter Review – STP3