CK-12 Physical Science Concepts - For Middle School

http://www.ck12.org Chapter 2. Matter

Summary

• The process in which water vapor or any other gas changes to a liquid is called condensation.


• The temperature at which condensation of water vapor occurs is called the dew point. The dew point varies
  depending on air temperature and moisture content.


• Condensation plays an important role in the water cycle. Without it, Earth’s water could not recycle.

Vocabulary

• condensation: Process in which a gas changes to a liquid.

Explore More

Use the dew point calculator at the following URL to answer the questions below.

http://www.dpcalc.org/

1. Find the dew point when the temperature and relative humidity of air have the values listed inTable2.6:

TABLE2.6:Temperature, Relative Humidity, and Dew Point

Temperature (°C) Relative Humidity (%) Dew Point (°C)

20 10

20 50

10 50

2. Based on the dew points you calculated, how is relative humidity related to dew point?


3. How is air temperature related to dew point?

Review

1. What is condensation? Give an example.


2. Define dew point. What factors influence dew point?


3. In the water cycle, how does water vapor in the atmosphere change to liquid water on the ground?