Lesson 12-4: What is the dew point?

What is the freezing point of water in the Celsius temperature scale?

0*

___________________________, water vapor in the air changes from a gas to a liquid.

As the temperature of the air drops,

Describe the process of condensation.

As the temperature of the air drops, water vapor in the air changes from a gas to a liquid.

When does the process of condensation take place?

Condensation occurs when saturated air cools to the dew point or below.

HYPOTHESIZE: Why doesn't frost form at temperatures above 0*C or 32*F?

Frost will only form bellow the freezing points of water.

What is the dew point?

The dew point is the temperature to which air must be cooled to reach saturation.

What happens to the relative humidity when the air becomes saturated?

Relative humidity reaches 100%.

What is dew?

When the temperature drops to or below the dew point, water vapor condenses out or the air, which forms drops of liquid water, called dew, on grass, bushes, and other surfaces such as car windows.

If the temperature of the air is colder than the freezing point of water, the water vapor that leaves the air will immediately ....

freeze into ice, which is called frost.

Warm air can hold _____ water vapor than cold air.

more

Condensation is the

process of changing a gas to a liquid.

The temperature to which air must be cooled to reach saturation is ...

the dew point.