Download AA Understanding Weather

Name
Date Class CHAPTER
21
4111
DIRECTED READING WORKSHEET
Understanding Weather
As you read Chapter 21, which begins on page 562 of your textbook, answer
the following questions.
A
A
Twisting Terror (p. 562)
1. What is Tornado Alley?
2. Name the states that are part of Tornado Alley.
Pre-Reading Questions
(p. 562)
Answer these questions in your ScienceLog now. Then later, you'll
have a chance to revise your answers based on what you've learned.
Start-Up Activity (p. 563)
3. What is the purpose of this activity?
Section 1: Water in
•
the Air (p. 564)
4. Weather is the condition of the
certain time and place.
at a
The Water Cycle (p. 564)
5. Plants release liquid water into the air. True or False? (Circle one.)
TEXAS EDITION, GRADE 8, UNIT 6 RESOURCES
167
Name Date Class Chapter 21 Directed Reading, continued
6. Water that flows across land and collects in rivers, streams, and
the ocean is called
7.
takes place when liquid water
changes into water vapor.
8. Rain, snow, sleet, and hail are all forms of
a. condensation.
c. precipitation.
b. runoff.
d. evaporation.
Humidity (p. 565)
9. Take a moment to read the Brain Food on page 565. What makes
hair become longer when it is humid?
10. Which kind of air holds the highest amount of water vapor?
a. warm air
b. medium-temperature air
c. cool air
d. dry air
11. As air temperature increases, the amount of water that air can
hold
12. Relative humidity compares the amount of water vapor in the air
amount of water vapor
with the
that the air can hold at a certain temperature.
13. Air that is holding all the water it can hold at a given temperature
is
14. Relative humidity is given as a
Condensation (p. 566)
15. Why do water droplets form on the outside of a glass of ice water?
16. Condensation happens when
further.
168 HOLT SCIENCE AND TECHNOLOGY
cools
Name Class
Date Chapter 21 Directed Reading, continued
17. When air cools to a temperature at which it is completely
saturated with water vapor, we say that the air has reached its
Mid-Section Review
A
(p. 566)
Now that you've finished the first part of Section 1, review what you
learned by answering the Mid-Section Review questions in your
ScienceLog.
A
A
Clouds (p. 567)
18. What is a cloud made of?
Choose the word in Column B that best matches the definition in
Column A, and write the corresponding letter in the space provided.
Column B
Column A
19. cloud that forms in layers
20. puffy, white cloud with a flat bottom
21. cloud that produces thunderstorms
22. cloud that produces continuous rain
23. thin, feathery, high-altitude cloud
a. nimbostratus
b. stratus
c. cirrus
d. cumulonimbus
e. cumulus
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a)
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24. If cirrus clouds get thicker, they indicate that
is coming.
25. In Figure 5 on page 568, the prefixes cirro-, alto-, and stratoclassify clouds by their
c. size.
a. temperature.
d.
altitude.
b. shape.
Precipitation (p. 569)
26. Before a cloud drop falls as rain, it must become about
its normal size.
a. 2 times
b. 10 times
c. 100 times
d. 1,000 times
TEXAS EDITION, GRADE 8, UNIT 6 RESOURCES
169
Name
Date
Chapter 21 Directed Reading, continued
Mark each of the following statements True or False.
Sleet forms when rain falls through a layer of freezing air.
28 Snow forms when temperatures are so warm that
water vapor changes directly to a solid.
29 Updrafts of air can send hail back up into the clouds.
30. Rain that does not freeze until it hits a surface near the ground is
called
27 Section Review
(p. 570)
Now that you've finished Section 1, review what you learned by
answering the Section Review questions in your ScienceLog.
Section 2: Air Masses and Fronts (p. 571)
1. What causes changes in weather?
2. The air in an air mass has the same
and
Air Masses (p. 571)
3. What is a source region?
4. What two characteristics of air masses are represented with a
two-letter symbol on weather maps?
c. moisture and temperature
a. density and moisture
d. shape and mass
b. mass and temperature
5. Give the four letters used to describe the characteristics of air
masses and tell what each letter identifies.
170 HOLT SCIENCE AND TECHNOLOGY
Class
Name Date Class Chapter 21 Directed Reading, continued
Fronts (p. 572)
6. Take a moment to read the Brain Food on page 572.
Meteorologists first started using the term front to describe
weather systems during World War I. They compared air masses
to opposing
a. armies.
c. submarines.
b. tanks.
d. machine guns.
7. Air masses that form from different areas often don't mix because
they have different
a. wind speeds.
c. clouds.
b. air pressures.
d. densities.
A
A
Choose the type of front in Column B that best matches the
description in Column A, and write the corresponding letter in
the space provided.
Column A
Column B
A warm air mass moves over a cold air mass.
9. A warm air mass is caught between two colder
air masses.
10. A cold air mass moves under a warm air mass
and pushes it up.
11. A cold air mass meets a warm air mass, but
nothing happens.
8.
ft
a. cold front
b. warm front
c. occluded front
d. stationary front
Section Review (p. 573)
Now that you've finished Section 2, review what you learned by
answering the Section Review questions in your ScienceLog.
ec
C
Section 3: Severe Weather
1.
(p. 573)
weather.
A thunderstorm is one example of
Thunderstorms (p. 574)
O.
0
2. Which one of the following atmospheric conditions produces
thunderstorms? (Circle one.)
a. Warm, moist air rises rapidly.
b. The air near the Earth's surface is cold and dry.
c. The atmosphere is stable.
d. The atmosphere is bright.
3. Cumulonimbus clouds can reach heights of more than
TEXAS EDITION, GRADE 8, UNIT 6 RESOURCES 171
Name Date Chapter 21 Directed Reading, continued
Mark each of the following statements True or False.
4. Lightning takes place when there is a difference in
charge between two areas.
Thunder is caused by the rapid expansion of air
5. along a lightning strike.
When lightning strikes, energy is transferred to
6. the air.
Tornadoes (p. 575)
7. What is the relationship between a funnel cloud and a tornado?
Indicate the correct order for the steps in the formation of a tornado
by writing the appropriate number in the space provided.
The column of spinning air travels to the bottom of
8. the cumulonimbus cloud.
Strong updrafts of air turn the column of spinning
9
air to a vertical position.
The funnel cloud touches the ground.
10 Wind moving in two different directions causes a
11. layer of air between them to spin.
12. Look at the Brain Food on page 576. What do you call a tornado
that happens over water?
c. a whirlpool
a. an aqueous tornado
d. a waterspout
b. a water funnel
13. In which seasons do most tornadoes in the United States occur?
c. spring and early summer
a. late summer and fall
d. winter and early spring
b. late fall and winter
14. Why are tornadoes so dangerous?
172 HOLT SCIENCE AND TECHNOLOGY
Class
Name Class Date Chapter 21 Directed Reading, continued
Hurricanes (p. 576)
15. A tropical weather system is classified as a hurricane when it
reaches wind speeds of at least
16. Hurricanes that form over the western Pacific Ocean are called
, while those that form over the
Indian Ocean are called
17. Hurricanes turn in opposite directions in the Northern and
Southern Hemispheres. True or False? (Circle one.)
18. Where do hurricanes get their energy?
A
A
A
Choose the term in Column B that best matches the description in
Column A, and write the corresponding letter in the space provided.
Column B
Column A
bands of clouds that circle the center
of a hurricane
20. cumulonimbus clouds that cause heavy rains
and strong winds
21. core of warm, calm air
19.
r.)
-c
a. eye
b. eye wall
c. rain bands
0
22. What causes most of the damage associated with hurricanes?
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a. flooding
c. cold weather
b. high winds
d. lightning
23. Look at the Astronomy Connection on page 578. The Great Red
Spot of Jupiter is most like a(n)
a. hurricane.
c. thunderstorm.
b. tornado.
d. air mass.
Section Review (p. 578)
Now that you've finished Section 3, review what you learned by
answering the Section Review questions in your ScienceLog.
TEXAS EDITION, GRADE 8, UNIT 6 RESOURCES
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Name
Date
Class
Chapter 21 Directed Reading, continued
Section 4: Forecasting the Weather (p. 579)
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1. What is a weather forecast?
Weather Forecasting Technology
(p. 579)
2. A barometer measures
An anemometer measures
3. Weather balloons carry electronic equipment that measures
conditions as high as
above the
Earth's surface.
4. Which of the following conditions is NOT measured by weather
balloons? (Circle one.)
a. air pressure
c. relative humidity
b. precipitation
d. temperature
Mark each of the following statements True or False.
Radar is used to determine wind speed and direction.
5. 6. Radar can be used to detect the location of precipitation.
Weather satellites can measure temperatures at
different altitudes.
Weather Maps (p. 580)
8. Give the full name and initials of two major sources of weather
information in the United States.
9. On a weather map,
are lines that
connect points of equal
10. What does an isobar line that forms a closed circle show?
Section Review
(p. 581)
Now that you've finished Section 4, review what you learned by
answering the Section Review questions in your ScienceLog.
174 HOLT SCIENCE AND TECHNOLOGY
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