Name: _________________________________
Date: __________________________ Block: _______
Where does water in the atmosphere come from?
Write true if the statement is true. If the statement is false, change the underlined term to make the statement
true.
____________________ 1. When water droplets form on the outside of a glass, it is because the glass is warmer
than the air around it.
____________________ 2. Water vapor is water in the form of a gas.
____________________ 3. The changing of a liquid to a gas is called condensation.
____________________ 4. Most of the water in the air evaporates from lakes.
____________________ 5. When a liquid is heated, its molecules move slower.
What is humidity?
PART A Match each term in Column B with its description in Column A. Write the correct letter in the space
provided.
Column A
Column B
__________ 1. filled to capacity
a. capacity
__________ 2. affects air’s capacity for holding water
b. relative humidity
__________ 3. actual amount of water vapor in air in g/kg
c. saturated
__________ 4. amount of material something can hold
d. specific humidity
__________ 5. percentage of water vapor in the air
e. temperature
PART B Circle the phrase in each pair that describes the air that can hold more water vapor.
1. warm air, cold air
2. air at 18ºC, air at 37ºC
3. 12 kg of air, 20 kg of air
Skill Challenge
Each cube stands for a volume of air. The dots in each cube stand
for molecules of water vapor. Use the diagram to answer the following questions.
1. Which air is driest, A, B, or C? __________
2. Which air is dampest, A, B, or C? ___________
3. Which air has the highest specific humidity? ________
4. Which air has the lowest specific humidity? _______
5. In which cube do you think rain most likely will occur? Explain. _______________________________________
__________________________________________________________________________________________________
Name: _________________________________
Date: __________________________ Block: _______
How is relative humidity measured?
Answer the following questions.
1. What is relative humidity? __________________________________________________________________
2. a. What is the relative humidity of air filled to half its capacity? ____________________________________
b. To one-quarter of its capacity? ____________________________________________________________
3. What happens to the relative humidity if the temperature goes up? __________________________________
4. Which is more comfortable—a temperature of 40°C and a low relative humidity or a temperature of 35°C and
a high relative humidity?
Explain: _____________________________________________________________
Skill Challenge
Use the table to complete the following.
1. What is the relative humidity if a psychrometer has the following readings?
Wet Bulb
Dry Bulb
a.
–5°C
0°C
b.
5°C
10°C
c.
17°C
20°C
d.
21°C
25°C
e.
30°C
35°C
Relative
Humidity
2. a. Which reading indicates the highest relative humidity? _______
b. The lowest? ______________________
3. Which two readings have the same relative humidity? ______
What is the dew point?
Complete each statement with one of the terms in the box below.
frost
dew point
liquid
solid
relative humidity
saturated
dew
condensation
cooled
1. As the temperature of air drops, water vapor changes from a gas to a ________________________________
2. The changing of a gas to a liquid is called ______________________________________________________
3. The temperature at which condensation takes place is called the ____________________________________
4. Condensation takes place when saturated air is __________________________________________________
5. If the air temperature drops enough, the air becomes ____________________________________ , and its
__________________________________________________________________ reaches 100 percent.
6. Drops of water resulting from condensation are called ____________________________________________
7. At 0°C, water changes from a liquid to a _______________________________________________________
8. Water vapor that condenses into ice is called ___________________________________________________