Lesson 1 in science grade 6

​Activity 1 can you explain

​when the water in the small puddle is heated, due to the transfer of thermal energy of the sun, it evaporates and changes into water vapor, so the small puddle is dried up and disappeared.

How do water, wind and sunlight affect energy transfer in water cycle :

• The sun is considered the most important source that affects the water cycle.

• Sunlight provides the energy needed to:

  - melting ice and changing it into liquid water.

  - Evaporating liquid water to form water vapor .

  - Generating the wind movement, where winds cause ocean currents that transport water to different locations on Earth.

• There was a large salt lake in Turkey, by passing time this lake became like a small puddle and sometimes it dries up completely in summer.

• This lake hosts huge numbers of flamingos that migrate and reproduce (breed) there when the weather is warm.

• Flamingos feed on algae that found in the shallow water of this lake.

• The energy transfer in the water cycle leads to

  completely drought of this lake due to increase in the evaporation of the lake water in summer.

So,scientists try to discover ways to conserve and rehabilitate the ecosystem at this lake and protect it from climate changes

​in this activity, we will study the process and steps that affect the water cycle:

1.Evaporation process.
2.Condensation process

3.Precipitation process.
4.Runoff
5. Collection.

• As you can observe in the opposite picture, the water cycle is affected by three main processes, which are evaporation, condensation and precipitation.

Evaporation process:

It is the process in which matter changes from liquid state to gas state

Byaosranon

Condensation process :

It is the process in which matter changes from gas state to liquid state.

Precipitation process :

It is the process in which water falls on Earth in the form of rain, sleet, snow or hail (snow pellets).

• After precipitation happen, the water cycle can be affected by two steps, which are runoff and collection.
Runoff :
It is the step in which water flows along the Earth's surface into the river and then into the ocean or sea.
Collection :
It is the step in which rainwater falling on the Earth's surface is collected in different water bodies.

​distribution of solar energy:

• The amount of the solar energy that reaches the Earth differs from one place to another on the Earth's surface.

• The distribution of the solar energy on the Earth's surface plays an important role in evaporation process in the water cycle, where the regions on Earth's surface can be classified into :

• Hottest regions: They are regions in which the evaporation process is the greates

• Moderate regions: They are regions in which the evaporation process is moderate

• Coolest regions: They are regions in which the evaporation process is the smalles