Download Chapter 11 Lesson 2

Chapter 11: Lesson 2
What Conditions Affect the Water Cycle?
Objectives:



Identify changes in states of water.
Describe the stages of the water cycle.
Explain how the water cycle relates to weather.
Vocabulary
water cycle
evaporation
condensation
humidity
precipitation
The Water Cycle
Air is always moving and just as air is always moving so is ________________.
Water continuously moves from Earth’s surface to the ___________________ and back
to Earth in a process called the ________________ ________________. The water
cycle is driven by ________________ energy from the sun. The sun’s rays warm the
water on Earth’s surface. The water ________________, leaving behind the salt in the
sea water. The sun also heats the atmosphere unevenly. This causes the air. Containing
________________ ________________, to move from one place to another.
The water cycle is important because people, plants, and animals need fresh water
to live. Without rain and snow, we wouldn’t have drinking water. Without the water cycle
there also wouldn’t be water to grow crops.
Water exists in three states, solid, liquid, and gas. Water is a
________________ in oceans, lakes, rivers, and in rain. When water is heated, it turns
into a __________ -- water vapor. If water is cooled enough, it changes into a
____________ - ice.
During part of the water cycle, liquid water changes into a ________ by the
process of ________________. When water is a gas, its molecules are spread out and
cannot be seen. Water that is in the air remains a gas as long as the air is warm. If the air
______________, the water becomes a ________________. Water changes from a gas
to a liquid in the process of _____________________. When a large amount of water
vapor condenses, a cloud forms. If the drops of water in the could become heavy enough,
the water falls as rain.
When rain falls on the land it runs into different places such as
___________________________________________________________________
__________________________. Some of the water also soaks into the ground and
rivers carry water back into the ocean. Water that is under the ground (water that is
soaked into the ground) is called ________________. This water also flows back to the
ocean or into streams and rivers.
Clouds and Precipitation
A large part of the water cycle occurs in the ________________. Water enters
the atmosphere when it ________________ and becomes ________________
________________. Some areas of the atmosphere have more water vapor than others.
The amount of water vapor in the air is called ________________. The
________________ water vapor in the air, the more humid the air is. As warm air is
forced up, it ________________. Some of the water vapor begins to
________________ on dust and other particles in the air. As more and more water
condenses, a ________________ forms. A cloud is basically dust and condensed water.
Small water droplets, inside the cloud join together to form larger droplets. The
larger droplets then join to make water drops. Water drops are too ________________
to stay in the atmosphere. These water droplets fall from the clouds as
________________. Precipitation is
__________________________________________________________________
_________________________________________________________. The forms
of precipitation are
__________________________________________________________________
______________________________. Rain is ________________ precipitation.
________________ precipitation is snow, sleet, and hail. Snow is formed when water
vapor turns directly into __________ ________________. Sleet and hail form when
liquid water passes through air that is cold enough to freeze the water drops.
Water vapor DOES NOT always form precipitation as it condenses. The ground
loses heat more quickly at night (land cools off more quickly than water in the evening).
When the ground becomes cold enough, ________________ ________________ in
the air directly above the ground condenses. This is the reason why dew forms in the
morning. If the temperature is very cold, frost forms on the ground or on the car
windows. Frost is water vapor that turns
________________________________________________. A similar weather
condition that forms dew/frost can also form fog. Fog is water vapor that has condensed
into ________________________________________________.
Interpret Visuals
1) At what height in the atmosphere does each kind of cloud form?
2) What does each type of cloud look like?
3) What kinds of weather does each kid of cloud bring?
Factors That Affect the Water Cycle
Many factors affect the water cycle. One of these factors is how close a place is
to Earth’s poles or the equator. Places that are close to the poles are always cold.
Because they are always cold they are more likely to get snow or sleet than places near
the equator since areas near the equator are warm.
The shape of the land also affects the water cycle. Air must move around
landforms such as mountain ranges. When air is pushed up the side of a mountain it
_____________. Most of the water in the air ________________ and causes rain to
fall on the side of the mountain. If the mountain is highest enough, snow may fall instead
of rain and the snow will stay on the mountain until spring. In spring, the snow melts
because of the warm temperatures and sends huge amounts of water flowing down the
mountain into streams and ________________. This is called ________________
________________.
Landforms such as ________________ also affect the water cycle. As air rises
over land, clouds form. If the drops of water in the clouds get large enough, rain falls.
These things affect the water cycle because they change the
________________ of the air. Warm air has lower pressure than cold air and warm air
can have more ________________ in it than cold air. Any factor that causes a change in
________________ ________________ can also cause a change in the water cycle.
To sum it up: In this lesson, you learned that the water cycle is responsible for the
movement of water in Earth’s atmosphere and on its surface. This cycle of is vital for all
living things. Water falls to Earth in many forms and is affected by different factors.