شرح ساينس الصف السادس الابتدائي لغات - الفصل الدراسي الثاني
شرح ساينس سادسة ابتدائي - ترم ثاني

لينك تحميل الملزمة
https://drive.google.com/file/d/1Q5dvQxS0noBFLuK50V4bg4FslCo2ayt4/view?usp=sharing

لينك تليجرام
https://t.me/mrahmedelbashagroup

In This Lesson:
▌Humans, animals and plants need fresh water to survive.
▌The water we need to live on Earth can be found in rivers, some lakes, ... etc.
▌Most of plants depend on rain that falls from the clouds in the sky to grow.

The water cycle in nature:
▌The water cycle provides water for all living organisms and regulate weather on our planet.
▌Nature recycles water, where the water cycle includes the continuous movement of water from their different resources to the atmosphere, then this water finally back to Earth in the form of rain , sleet, snow or hail.
▌You have known from the previous activities the processes and steps that form and affect the water cycle which are evaporation, condensation, precipitation, collection and runoff.

In this figure, we will explain how water moves through the water cycle from water bodies to the atmosphere, then back to the Earth's surface to start the water cycle all over again.

Convection
It is the process in which heat transfers in liquids and gases, where hot molecules (less density) rise upward, while colder molecules (more density) fall down.
▌The heat of the Sun transfers from space to Earth's atmosphere by radiation .
▌This heat can transfer through Earth's atmosphere also by convection in the form of convection currents.
▌The unequal heating of land and oceans causes difference in temperatures and densities in water of oceans and atmosphere.

Convection in liquids and gases:


The relationship between convection and condensation:
▌Convection causes the rising of temperature of air that contains water vapor.
▌Condensation happens when this rising air loses its heat and the cold water vapor changes into water droplets and finally this leads to formation of clouds.
 
The Heating of Earth
Getting closer to the equator or moving away from it affects the weather, where:
▌The weather of the areas near the equator is hot and humid.
▌The weather of the areas as we move away to north and south of the equator depends on the temperature and precipitation at these areas, where:
- The weather could be warm and humid.
- Or, the weather could be freezing cold.

Now, let's study how the inclination of sun rays affects the weather.
• In the figure (1), when the sun rays fall perpendicular on Earth's surface in the area near the equator, the sun rays are concentrated on a small area giving high effect of heat,
so the weather is hot.


• In the figure (2), when the sun rays fall semi-inclined (semi-slanted) on Earth's surface in the area at the north and south of
the equator, the sun rays are distributed on a large area giving low effect of heat, so the weather is warm.


• In the figure (3), when the sun rays fall very inclined (very slanted) on Earth's surface in the area faraway from the equator, the sun rays are distributed on a very large area giving the lowest effect of heat, so the weather is very cold.


بالتوفيق
مستر احمد الباشا