Grade 5 Science February Revision
Concept 3.1
بفكركم أن المراجعة دي ليها فيديو شرح كل نقطة بالتفصيل ببساطة عشان يبقى كله سهل عليكم بإذن الله … و علشان تلاقى الفيديو اكتب فى اليوتيوب Dr.Rania Science و هيظهرلك كل حاجة .. او ابعتلى واتساب على رقمى 01029919557 هدخلك الجروب الخاص بيا و ابعتلك الفيديوهات ..بالتوفيق ليكم
و لو عايزين مراجعات MATHS و ICT بنفس الشكل ابعتولى على الواتس برضو
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هنراجع دلوقتى الكونسيبت الاول فى الترم الثانى كامل يلا بيناااا و انت مشغل الفيديوووو
v Main points:
Ø The Earth into four main systems (or spheres) which are : Atmosphere , Hydrosphere , Biosphere and Geosphere
Ø Atmosphere : It is the system that surrounds the Earth and it is composed of mixture of some gases such as nitrogen, carbon dioxide, water vapor, … etc.
– The word “Atmos” means “Vapor“.
– The atmosphere is usually called “air“
Ø Hydrosphere : It is the system that includes all water on the Earth (fresh water and salt water).
The word “Hydro” means “Water“.
Ø Biosphere : It is the system that includes all living organisms such as humans , plants, animals, microorganisms…. etc.
– The word “Bio” means “Life“.
Ø Geosphere: It is the system that includes rocks, soil, sand ,Minerals, Landforms (such as mountains, valleys, … etc.). ··· etc.
– The word “Geo” means “Earth“.
– It is also known as “Lithosphere“.
Ø Water can affect nonliving things as it causes weathering and erosion of rocks on the Earth’s surface.
Ø Weathering : It means the breakdown of rocks into smaller particles due to the effect of rain, wind, temperature, … etc
Ø Erosion : It means the transportation of small particles of rocks to another place by water or wind.
Ø Biome :It is a large area of the world that has similar soil, climate, plants and animals (wildlife). Examples of biomes : Deserts – Forests – Rainforests – Grasslands – Wetlands.
Ø 71 % (three-quarters) of Earth is covered by water, so our planet looks like a blue marble from space.
Ø Salt water : – It forms about 96.5 % of water on Earth.
Ø Fresh water : – It forms about 3.5 % of water on Earth.
Ø The total amount of water on Earth does not change, even if water changes from one state to another, so we cannot make new water, but we can recycle water.
Ø Water bodies on Earth can change from liquid state to :
– Solid state (ice) by freezing in extreme cold weather.
– Gas state (water vapor) by evaporation in hot weather.
Ø The Importance of water :
– Humans and animals drink water to survive.
– Plants need water to grow.
– Some animals and plants live in water.
Ø The Uses of water:
– Humans use water in many purposes such as : Generating electricity – Agriculture – Preparing food – Bathing – Recreation – Travelling – Cleaning – Manufacturing.
Ø The Water is one of the renewable resources on Earth because it can be replaced in nature through the “water cycle“.
Ø During water cycle in nature :
– Water present in water bodies on Earth evaporates.
– Water vapor collects in the air forming clouds.
– Water returns back to the Earth’s surface in the form of rains. Water returns back to the Earth’s surface in the form of rains.
Waterbodies on Earth
Oceans and seas : They are large water bodies that always contain salt water. Lakes: They are water bodies surrounded by land.
Most of lakes contain fresh water and some of them . contain salt water.
Rivers: They are water bodies that always flow from area f h. places) to areas with lower altitude (lower place) to higher altitude They always contain fresh water
Groundwater: It is the water that lies beneath the Earth’s surface due to the leakage of water into Earth through a layer of porous rocks. It always contains fresh water.
Most of fresh water on Earth is found in the form of frozen water as large pieces of ice known as “Glaciers.
Aquatic ecosystems can be classified into : Saltwater ecosystems and Freshwater ecosystems
Saltwater ecosystems
Ø Shallow areas which contain coral reefs and intertidal zones
Intertidal zone is the area along the coast that disappears underwater at the high tide and appears at the low tide
Ø Deepest areas which are called abyssal zones these areas are very deep, so that sunlight cannot reach them.
Examples of saltwater lakes : Lake Assal in Djibouti and Lake Bardawil in Egypt.
Lake Assal : It has a high concentration of natural salts, so it is too salty for fish and most aquatic animals to live in.
Also, there are few plants that can grow in this area. There are many different types of bacteria live in it .
Freshwater ecosystemsو فيه جدول تحت بص عليه حلو اوى
Ponds and most lakes
Flowing water bodies
Example of freshwater lakes : Lake Nasser in Egypt
Ø Give reason for:
1. Water is important for all plants on Earth. ·
Because all plants need water to grow and some of them live in water.
2. Water can affect nonliving things like rocks.
Because water can cause weathering and erosion of rocks.
3. Our planet looks like a blue marble from the space.
Because about 71 % of Earth is covered by water.
4.Water that forms the hydrosphere is one of the renewable resources on Earth.
Because water can be replaced in nature through water cycle.
5.Hiding of worms inside the soil is an example of an interaction between two
Earth’s spheres.
Because worms belong to biosphere, while soil belongs to geosphere.
6.Importance of atmosphere for plants in making their food.
Because plants take in carbon dioxide gas from air during photosynthesis process.
7. Most of fresh water on Earth can’t be used for drinking.
Because most of fresh water on Earth are in the form of frozen water.
8. Some ponds and lakes may dry up during some months.
Because when the temperature increases in summer, water evaporates faster.
9. No green plants can survive in the abyssal zones of oceans.
Because the abyssal zones don’t receive sunlight, which is important for making food in plants.
v What happens if
1. To the state of water when it is subjected to extreme cold weather.
It will be changed into solid state (ice).
2. If plants can’t get carbon dioxide from air.
They will not be able to make their food by photosynthesis process.
3. To animals that live in lakes if they dry up.
They have to adapt to the changes that happen, or they will die.
