Download 12.1 What is mechanical weathering?

Name
Class
Date
12.1 What is mechanical weathering?
Lesson Review
Complete each statement with a term from the list. Write your answers in the spaces provided.
contract
expand
mechanical weathering
chemical weathering
abrasion
ice wedging
root action
weathering
exfoliation
1. The process by which rocks on Earth’s crust are broken down is called
.
2. Physical changes in rocks, such as size and shape, occur during
.
3. The chemical makeup of rocks is changed during
.
4. During the day, heat causes the outside of rocks to
, or become larger.
5. At night, the outsides of rocks cool and
.
6. When water inside rocks freezes and melts over and over again,
7.
occurs.
__________________________ occurs in a river when rocks tumble and scrape against each other.
8. If a tree causes a sidewalk to crack, mechanical weathering called
9. In
has taken place.
rocks weather by peeling off in sheets rather than in grains.
Skill Challenge
Skills: analyzing, classifying
Decide which kind of mechanical weathering is described by each statement.
In the space provided, write T for temperature change, I for ice wedging, and R for root action.
1. After a harsh winter, a street has many potholes.
2. Cracks appear in a sidewalk near a tree.
3. A stone wall begins to crumble after several winters during which ice formed in its
cracks.
4. The outside of a rock peels off from repeated heating and cooling.
5. Cracks develop between the bricks of an ancient stone ruin among the trees in a jungle.
Name
Class
Date
12.2 What is chemical weathering?
Lesson Review
Match each term in Column B with its description in Column A.
Column A
Column B
1. topography that the dissolution of limestone creates
a.
moss
2. causes chemical changes in rocks
b.
oxidation
3. reaction between oxygen and another substance
c.
carbonic acid
4. iron oxide
d.
karst
5. mineral containing iron
e.
pyrite
6. chemical reaction between water and another substance
f.
carbon dioxide
7. a gas in the air
g.
chemical weathering
8. carbon dioxide dissolved in water
h.
rust
9. rock made of calcite
i.
hydrolysis
10. acid-producing plant
j.
limestone
Skill Challenge
The equations below represent chemical reactions. The substances that combine are shown on the left of the
arrow. The new substance that is produced is shown on the right of the arrow. In the space provided, identify
each chemical reaction as an example of hydrolysis or oxidation.
1. oxygen + a mineral → a new compound
2. water + feldspar → clay
3. oxygen + copper → green substance
4. oxygen + iron → iron oxide
Decide if the following descriptions are examples of chemical weathering or mechanical weathering.
5. A large rock falling from a cliff breaks into pieces.
6. Acids from plants break up rock.
7. Rocks carried by rivers have become smaller and more round by abrasion.
8. The oxidation of minerals containing iron rust.
9. Formation of potholes on streets during winter due to “ice wedging”.
10. Limestone dissolved by carbonic acid.