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Concept One Sustainability of Life in Ecosystems From the Perspective of Scientific Integration Chapter One: The Aquatic Ecosystem Chapter Two: The Atmosphere Chapter Three: S...

Concept One Sustainability of Life in Ecosystems From the Perspective of Scientific Integration Chapter One: The Aquatic Ecosystem Chapter Two: The Atmosphere Chapter Three: Soil Chapter Four: The Role of Science in Environmental Sustainability  Chapter One: The Aquatic Ecosystem Learning Outcomes Upon completing the study of this chapter, the student will be able to: 1. Identify the water layer and its relationship with other layers on planet Earth. 2. Explain the role of the water cycle in nature in causing various environmental changes. 3. Describe the chemical interactions in the aquatic ecosystem and their impact on water quality and the sustainability of marine life. 4. Illustrate the effect of the physical properties of water, such as specific heat, and surrounding physical factors like temperature and pressure on the distribution of living organisms and the sustainability of the aquatic ecosystem. 5. Evaluate the biological adaptations of living organisms in the aquatic environment and their role in the sustainability of the ecosystem. Related Issues 1. Water pollution 2. Climate change 3. Sustainability of water resources 4. Conservation of biodiversity 5. Water resource management 6. Sustainability challenges in light of population growth. Chemical Reactions and Their Impact on Water Quality Every time you drink a glass of water, have you thought about the chemical reactions that might occur within this vital liquid? Water is not just a transparent liquid; it is a medium in which many chemical compounds can react, affecting water quality and the health of living organisms that depend on it. In this chapter, we will learn about the water cover and the water cycle in nature, as well as some of the physical properties and basic chemical reactions that occur in water, and how these properties and reactions can affect environmental components. Water is characterized by its unique The Atmosphere properties that support life, as it can dissolve many chemical substances and The Biosphere can exist in all three states of matter: solid, liquid, and gas, within the known The water cover The rock cover temperature ranges on the Earth's surface. Water is essential for the continuation of life on Earth. All forms of life have a membrane that separates the organism from its environment. Water passes from the environment into the living cell through this membrane, carrying the necessary materials for energy production and also removing waste to the outside.  The Different Covers on Planet Earth The water cover distinguishes planet Earth from other planets in the solar system and refers to water in its liquid state on the planet, covering about 70% of the Earth's surface. Approximately 97% of this liquid water is found in oceans, seas, and salt lakes as saline water. The remaining part represents fresh water found in rivers, freshwater lakes, and groundwater. Water vapor (water in its gaseous state) is considered one of the components of the atmosphere. There is also the ice cover, which refers to frozen water in regions. Egypt is characterized by the diversity of its water bodies, which include the Nile River, the Gulf of Suez, the Gulf of Aqaba, the Red Sea, the Mediterranean Sea, and many saline and freshwater lakes. The Water Cycle in Nature Water exists on the Earth's surface or near it in a constant state of change between its three states, and it continuously moves from one place to another through many different pathways, forming an almost closed system known as the water cycle in nature or the hydrological cycle. The water cycle as a system is capable of physically, chemically, and biologically altering the Earth's surface. The water cycle in nature primarily includes the process of evaporation, which contributes to cloud formation, and the process of precipitation, whether rain or snow. In addition to other processes such as biological processes like transpiration in plants and respiration in plants and animals, and the processes of water infiltration through the pores of soil and sedimentary rocks to form groundwater. Water vapor in the clouds may chemically react with compounds present in the air, forming some acids that fall as acid rain, which contributes to the weathering of rocks. **Research Activity** Through various sources, search for: 1. What are the different tools and instruments used by meteorologists to measure the annual rainfall amounts that fall on a specific area of the Earth's surface? 2. Can scientists predict future changes in the water cycle on Earth? **Chemical Composition of Water:** Water is composed of two elements: hydrogen and oxygen in a volume ratio of 1:2, respectively, while oxygen accounts for 88.89% of the mass of a water molecule and hydrogen accounts for 11.11%. The two hydrogen atoms are bonded to the oxygen atom by two covalent bonds that form an angle of approximately 104.5° between them. **Chemical Properties of Water:** Water does not exist on the Earth's surface in a pure form, as it contains many ions and chemical substances that interact with it in various ways. We will discuss three main properties of water:  1. **Polarity of Water:** The oxygen atom has a higher electronegativity than the hydrogen atom; therefore, the electrons in the bond are attracted toward the oxygen atom, creating a partial negative charge on the oxygen atom and a partial positive charge on the hydrogen atom. This is known as the polarity of the water molecule. The polarity of water molecules leads to their interaction with other water molecules through hydrogen bonds or with polar molecules of other substances, giving water the ability to dissolve many salts and break them down into hydrated ions. Example Dissolution of sodium chloride in water: NaCl + H₂O (s) → Na⁺ (aq) + Cl⁻ (aq) Example: The ability of water molecules to form hydrogen bonds with each other is a fundamental reason for the high boiling point of pure water, which reaches 100°C under normal atmospheric pressure, compared to the boiling point of similar compounds like hydrogen sulfide, which boils at 61°C. - Hydrolysis: A small percentage of water molecules exist as hydrogen ions (H⁺) and hydroxide ions (OH⁻). As a result of chemical reactions with various compounds, hydrolysis occurs for some salts present in natural waters, affecting the balance of these ions, leading to either acidity or basicity of the water. Practical example: When table salt (NaCl) is added to water, it dissociates into sodium ions (Na⁺) and chloride ions (Cl⁻), and the salt ions remain in the solution without bonding with water ions, making the solution neutral since the concentration of hydrogen ions (H⁺) equals the concentration of hydroxide ions (OH⁻). In the case of sodium bicarbonate (NaHCO₃), hydrolysis occurs, leading to a decrease in the concentration of hydrogen ions (H⁺) and an increase in the concentration of hydroxide ions (OH⁻), making the salt solution basic. Conversely, when ammonium chloride (NH₄Cl) is dissolved in water, it undergoes hydrolysis, resulting in a decrease in the concentration of hydroxide ions and an increase in the concentration of hydrogen ions, making the salt solution acidic. Acid-Base Balance The acid-base balance depends on the relationship between the concentration of hydrogen ions (H) and hydroxide ions (OH) in water. This relationship can be identified through the value of what is called the pH of the solution, which is a graduated scale ranging from 0 to 14. If the concentration of H increases, the water becomes acidic, and the pH value is less than 7. If the concentration of OH increases, the water becomes basic, and the pH value is greater than 14. While if the concentrations of the two ions are equal, the water is neutral, and the pH value equals 7. The pH value is a measure that expresses the acidity or basicity of water. Pure water has a pH of about 7, which is considered neutral. However, this number may vary in natural environments, affecting the living organisms that inhabit them.  The pH value of water from different sources: - Seawater: The pH value of seawater generally ranges from 7.5 to 8.4, depending on the region where the sea is located and the surrounding environmental factors. - Freshwater: The pH value of rivers and lakes usually ranges naturally between 6.5 and 8.5. - Distilled water: The pH value is about 7, as it is free from most impurities and ions that contribute to the acidity or basicity of other natural water sources. - Groundwater: The pH value of groundwater varies from one area to another depending on several factors, the most important of which is the geological composition of the area. Groundwater can be either neutral or basic, and its pH value varies due to exposure to calcium carbonate or magnesium carbonate rocks. The pH of clouds is generally slightly acidic, with values ranging from 4.5 to 5, due to the presence of dissolved carbon dioxide and other acidic gases in water droplets. These values can vary depending on different environmental factors and human activities in the area that can affect the pH level during cloud formation or rainfall. Scientific Activity Measuring pH Variation in Different Water Samples: To measure the pH value of different water samples (sea water, river water, and spring water), you can conduct the following experiment: Required Materials 1. Water samples (sea water, river water, and spring water) 2. pH meter or pH test strips 3. Cups for samples 4. Distilled water for calibration 5. Stirring rod Experimental Procedure: 1. Calibration: Calibrate the pH meter according to the manufacturer's instructions using distilled water. 2. Sample Preparation: Label the cups according to the type of water sample and add a small amount of each type to each cup. 3. Testing: Immerse the electrode of the calibrated pH meter into each sample and record the reading once it stabilizes. 4. Measurement Using Test Strips: If using test strips, dip the strip into each sample for a few seconds and then compare its color with the attached chart to determine the approximate pH value. Research Activity Conduct a research project with a group of your colleagues, supported by statistical data, showing the differences in pH levels of clouds and rain and the reasons for that, in each of the following: A. Industrial cities B. Agricultural areas C. Coastal cities To reduce the potential negative effects on water quality and the health of living organisms due to saline water decomposition and its impacts on water chemistry, it is important to closely monitor salinity levels as well as changes in ionic composition within natural water area Proper waste disposal practices reduce the addition of harmful salts to water bodies, maintaining water quality for wildlife habitats and human consumption purposes. Check Your Understanding 1. Multiple Choice Questions Which of the following represents the percentage of freshwater on the surface of the Earth? A. 50% B. 3% C. 97% D. 70% Explain how a change in the pH value of river water can affect the surrounding ecosystem. Provide suggestions for improving the water quality in this river. Design an experiment to study the effect of different chemicals on water quality, and specify how the results of this experiment can be used to preserve aquatic environments.  1-2 The Physical Properties of Water and Their Role in the Distribution of Living Organisms Water has unique physical properties that distinguish it from other fluids, liquids, and gases, such as the decrease in its density upon reaching the freezing point and its high specific heat, which affects many natural phenomena and the distribution of living organisms in different environments. Density: It is the mass of a unit volume of a substance at a specific temperature. Since matter is made up of molecules, the density of a substance depends on the mass of the molecules and the spaces between them. In the case of pure water, the mass of 1 cm³ at 4°C is equal to 18, meaning that the density of water at 4°C is 1 g/cm³, equivalent to 1000 kg/m³ in SI units. As the temperature of water decreases from 4°C to its freezing point, its density decreases, as shown in the accompanying figure. The ratio of the density of a specific substance to the density of pure water at the same temperature is known as the relative density of the substance. The density of liquids or their relative density is measured using a hydrometer, which is a sealed hollow glass container with a wider bottom part for buoyancy. It contains balls of lead (or mercury) that help maintain vertical balance. Its container is connected to a long glass stem with a small diameter, graduated in density units, where the lower scale indicates the highest density measured by the hydrometer and the upper scale indicates the lowest density measured by the hydrometer, as shown in the accompanying figure. Scientific Activity Measuring the Density of Different Water Samples Using a hydrometer to determine the density of water from different sources (sea/rivers/canals/ponds/lakes/groundwater). Discuss how a hydrometer can be used to predict the presence of dissolved pollutants in a water sample. Water Density and Ocean Currents The density of ocean water is affected by both the pressure within it, the amount of dissolved salt, and its temperature. As pressure increases with depth, water molecules come closer together, thereby increasing density. Density is also affected by the amount of dissolved salt (salinity) in the water. The higher the salinity of the water, the higher its density. The normal salinity level of ocean water is 35 grams per liter of water (or the equivalent of two teaspoons per cup of water). Finally, the temperature of the water affects its density; as the temperature decreases (down to 4°C), the molecules come closer together, occupying less volume and thus increasing density. Variations in water density are one of the reasons for ocean currents. Ocean currents transport heat and salt from tropical regions to the polar regions of the Earth, as well as nutrients from the depths of the ocean to the surface and freshwater from rivers or melting glaciers to various locations during their journey around the world.  **Water Density in Polar Regions** The density of water changes with temperature. Generally, the volume of a liquid increases with rising temperature and decreases with falling temperature. Water is an exception to this rule. As the temperature of pure water rises from (0°C) to (4°C), the water contracts and thus its density increases, reaching its maximum value of (1000 kg/m³) at 4°C. Water expands with rising temperatures above 4°C, and consequently, its density decreases. This helps to understand why ice forms on the surface in polar regions instead of at the bottom. When the air temperature is between 4°C and 0°C, the surface water of the lake expands and becomes less dense than the water below it. Eventually, the surface water freezes, and the ice remains on the surface since the density of ice is less than that of water, while the water near the bottom stays at 4°C. If this were not the case, fish and other marine life would not survive.  **Experiment: The Effect of Density Differences on Water Movement** Make ice cubes by adding food coloring to the water before it freezes to facilitate observing the melting process of the ice cubes and the direction of water movement after they melt. Place one ice cube in a quantity of fresh water and another in an equal amount of salty water, where the salt concentration is equivalent to that of ocean water at room temperature. In which case does the ice cube melt faster? What are your observations on the water movement resulting from the melting of each cube? This is what actually happens in the ocean; when fresh water from melting glaciers enters the ocean, this fresh water spreads on the surface and does not sink. If this fresh water freezes, it forms an insulating layer between the...  Check your understanding.. Analyze the corresponding graph and deduce what happens to the density of water with changes in temperature. illustrate how the change in temperature and the density of water affects living organisms at in an aquatic environment. Oxygen and Carbon Dioxide in the Aquatic Environment It is natural for rivers and seas to maintain sufficient levels of oxygen gas and carbon dioxide gas for the continuation of aquatic life, including plants, marine animals, fish, and microscopic organisms like bacteria and algae. -- Oxygen is present in a small proportion in water, and its main source is the atmospheric air. In addition to the role played by phytoplankton, algae, and aquatic plants through the process of photosynthesis in producing oxygen in water. In seas and oceans, more oxygen dissolves in water due to waves and disturbances within the environment, which can enhance gas exchange between the atmosphere and water. In general, these natural processes provide marine creatures with the dissolved oxygen necessary for their survival.  Solubility of the gases in water The concentration of oxygen gas in the air is about 500 times higher than the concentration of carbon dioxide gas, but oxygen gas is about 50 times less soluble in water. The solubility of gases in saline ocean water is about 20-30% lower than their solubility in freshwater. Generally, the solubility of gases decreases at higher temperatures; as the temperature rises, the concentration of dissolved carbon dioxide in water decreases at a greater rate than the concentration of oxygen in water. The graph illustrates the relationship between the solubility of oxygen and carbon dioxide in freshwater at different temperatures under the natural composition of atmospheric air. Effect of increased levels of dissolved oxygen in water: 1. Enhanced respiration: Aquatic organisms rely on dissolved oxygen in the water for respiration. An increase in the amount of oxygen in the water improves their respiratory capacity. 2. Improved metabolism: High levels of dissolved oxygen can support the metabolic processes of aquatic organisms and enhance growth. 3. Increased activity: Adequate levels of dissolved oxygen stimulate aquatic organisms to be more active in swimming, hunting, and reproduction. 4. Maintaining ecosystem balance: A healthy balance of dissolved oxygen in water is crucial for sustaining a stable aquatic ecosystem by supporting diverse populations of fish, invertebrates, and plants. Research activity: Investigate various sources regarding the factors that lead to a decrease in the levels of dissolved oxygen in water and the implications of its deficiency. Sources of carbon dioxide in the aquatic environment: The atmosphere is the primary source of carbon dioxide (CO2) in water, as carbon dioxide is exchanged between the atmosphere and water. Marine organisms produce carbon dioxide gas that dissolves in the surrounding water as one of the waste products from metabolic processes. Human activities such as industrial pollution and the decomposition of organic materials carried by agricultural runoff. The impact of increased carbon dioxide gas levels in water on aquatic organisms: An increase in carbon dioxide (CO2) levels in water can have several negative effects on aquatic organisms, including: - Acidification: When carbon dioxide levels are high in the atmosphere, it can dissolve in greater concentrations in water, leading to an increase in carbonic acid and a decrease in the pH value of the water. This acidification can be harmful to many species of aquatic organisms, especially those that go through sensitive life stages such as the egg and larval stages. - Impaired respiration: High levels of carbon dioxide can lead to a decrease in the dissolved oxygen levels in water, which is essential for the respiration of aquatic organisms. - Reduced calcification: Many marine organisms, such as corals, mollusks, and some types of plankton, rely on calcium carbonate to form their shells or skeletons. This substance is a poorly soluble solid in water, and an increase in carbon dioxide levels converts it into calcium bicarbonate, which dissolves in water, hindering these organisms' ability to build or maintain their structures. The impact of decreased carbon dioxide levels in water on aquatic organisms: - Reduced photosynthesis: Aquatic plants and algae require carbon dioxide for photosynthesis. A decrease in the availability of carbon dioxide can limit their ability to produce energy, affecting the overall productivity of the ecosystem. - Impact on food chains. The impact on food chains can be influenced by changes in the level of carbon dioxide in water, affecting producer organisms such as phytoplankton and algae, and consequently impacting organisms at higher levels of food chains‫ذ‬. pH imbalance: Low concentrations of carbon dioxide may lead to an increase in pH, negatively affecting sensitive species that are adapted to a specific pH range. 1-3 Biological Adaptations of Living Organisms in Aquatic Environments: In the world of aquatic creatures, each living organism possesses a set of adaptations that help it survive in its aquatic environment, whether in deep oceans or shallow lakes. How do fish adapt to changes in temperature? How can organisms survive in saline or low-oxygen aquatic environments? In this lesson, we will explore these physiological, behavioral, and structural adaptations that allow aquatic organisms to live in diverse environmental conditions.  Physiological (Functional) Adaptation Living organisms in aquatic environments develop specific physiological adaptations that enable them to survive in their habitats. These adaptations or modifications in the way they perform their essential functions, for example, some deep-sea fish have special abilities to regulate breathing in conditions of low oxygen. To adapt to the high water pressure at depths, deep- sea fish have strong and resilient arteries and veins that withstand high pressure. They also have the ability to effectively adjust their blood pressure to remain consistent with external pressure. One famous example of these fish is the Electric Eel, which lives at depths reaching thousands of meters, where oxygen levels are extremely low. These fish have developed very large gills, with tiny capillaries that increase the efficiency of extracting the little oxygen available in the water. Additionally, they can slow down their metabolism to reduce their oxygen needs.  Osmosis and Osmotic Pressure Osmosis is the phenomenon of the movement or diffusion of water from a dilute solution to a concentrated solution through a semi-permeable membrane that separates the two solutions as shown in the figure. Osmotic pressure is the pressure resulting from the presence of a difference in the concentration of the solution due to the presence of the solute, which leads to the diffusion of water by osmosis. Thus, the solution with a higher concentration has a higher osmotic pressure than the solution with a lower concentration, which causes it to draw water from the less concentrated solution as shown in the figure. Scientific Activity Tools: Sugar solution, flower funnel, aluminum paper, glass cup with tap water Rubber band, holder Steps: 1. Secure the solivan paper tightly over the opening of the funnel with the rubber band. 2. Fill the funnel with the sugar solution, then immerse it in the cup filled with water and hold it vertically. 3. Mark the stem of the funnel at the level of the solution. 4. Leave the device for a sufficient period and observe what happens, recording your observations. We observe the rise in the level of the sugar solution in the stem of the funnel due to the increase in its volume from the cup by osmosis, as the concentration of sugar in it is higher than the concentration of sugar in the water in the glass cup.  Freshwater organisms physiologically adapt to low osmotic pressure. The previous experiment clarified what can happen to a living organism that resides in freshwater due to the osmotic pressure of the water being lower than the osmotic pressure of the solutions in those organisms' bodies. In this case, the bodies of those organisms absorb large amounts of water through their contractile vacuoles, leading to their rupture and death. So how do these organisms adapt to the characteristics of freshwater environments? Single-celled (unicellular ) organisms such as amoeba, paramecium, and euglena possess a structure called the contractile vacuole, which collects excess water within the cell and then expels it through the cell membrane as shown in the diagram. As for multicellular organisms like fish, they eliminate excess water that enters their bodies through the skin, mouth, and gills via the kidneys in the form of dilute urine. The kidneys in fish are located in the abdominal cavity on either side of the vertebral column as depicted in the diagram. Fish living in saltwater need to ingest large amounts of water to compensate for water loss from their bodies through osmosis, and their source is the highly saline seawater. They then excrete the excess salts through the kidneys and specialized cells in the gills. Among the physiological adaptations to cope with high salinity in oceans and seas, we find that sharks maintain water and salt balance within their bodies through a special mechanism that regulates the level of urea in their blood, where urea is a nitrogenous compound excreted in the urine of many animals. Sharks retain a high concentration of urea in their blood, which increases the Osmotic pressure, to become close to the osmotic pressure of the surrounding water. This helps reduce water loss from its body to the surrounding high- salinity environment. Behavioral adaptations Behavioral adaptations include specific behaviors or actions that living organisms undertake to avoid harsh conditions or to better exploit available resources. For example, some fish migrate between freshwater and saltwater for breeding and survival. Salmon are born in freshwater, then move to the sea where they spend most of their adult lives before returning to the rivers again to spawn. When salmon eggs hatch, their young spend the first part of their lives in freshwater. During this stage, the young adapt to the freshwater environment. Upon reaching a certain size, the fish undergo a biological process known as "Smoltification," which prepares them for the transition to saltwater in the sea. When salmon reach sexual maturity, they begin to return to the rivers where they were born to spawn. The salmon's ability to transition between different environments is due to its capacity to make complex physiological adaptations. For example, its circulatory system and respiratory system adapt to changes in salinity and varying amounts of oxygen in freshwater and saltwater. Structural adaptations Structural adaptations involve changes in the physical structure of living organisms that help them survive in their environments. For instance, fish that live in the depths of the oceans have large eyes. Their bodies compressed to withstand very high pressure in deep waters. An example of compressed fish in the depths is the (ice fish) , which lives in the cold southern oceans at depths of up to 2000 meters. Among the general structural adaptations of fish are the streamlined body that reduces water resistance to the movement of the fish, and the gills that enable it to extract dissolved oxygen from the water. Its body is covered with scales and mucus to be water-resistant and reduce water resistance during swimming. Additionally, the fins are the organs of movement, and bony fish have a swim bladder or buoyancy sac that helps them float in the water. Gas exchange and cellular respiration Gas exchange is the process by which an organism obtains oxygen from the atmosphere or the surrounding environment and eliminates carbon dioxide. Cellular respiration is a vital process carried out by living organisms to break the bonds in food molecules, especially glucose, to obtain stored energy. Single-celled organisms like amoebas obtain oxygen and eliminate carbon dioxide through the cell membrane by diffusion. Activity Analyze the relationship between biological adaptations and the aquatic environment. Research on the internet to find the biological adaptations present in the lionfish and the colored octopus. Lionfish Colored octopus Check your understanding Choose the correct answer: 1. Which of the following is a physiological change in ocean fish? A) Compressed body B) Strong arteries C) Increased blood pressure D) Large gills 2. Which of the following adaptations allows deep-sea fish to coexist with low oxygen levels? A) Slowing down the metabolic rate B) Compressed body C) Increased salt concentration in cells D) Strong blood vessels 3. What type of osmotic adaptation do salmon have? A) Behavioral adaptation B) Gas exchange organ C) Structural adaptation D) Physiological and structural adaptation 4. Which of the following is a similarity between amoebas and fish? A) Cellular respiration B) Physiological adaptation C) Body complexity D) Physiological and structural adaptation 5. Which of the following helps reduce water resistance to fish movement in water? A) Scales only B) Mucus only C) Mucus and streamlined body D) Streamlined body, mucus, and scales 6. Physiological adaptations require structural adaptations to occur. Give one example of this. 7. What challenges do deep-sea fish face and how do they adapt structurally? 8. What is the effect of freshwater on the osmotic pressure of freshwater organisms and how do those organisms cope with that effect? 1- The Effect of Heat on the Marine Environment Have you ever wondered how temperature affects marine organisms? Or why oceans remain warm even after sunset? And why on a hot summer day, you feel that the air around you has quickly become hot, while the water in lakes and rivers remains cooler? Heat and Temperature Some people confuse the concepts of "heat" and "temperature" in everyday conversation. Although they are related, there is a difference in their meanings in physics. Any body or system consists of a vast number of particles that are separated by spaces and are in a state of continuous motion. The sum of the potential energy resulting from the position of the particles relative to each other and the kinetic energy resulting from the motion of the particles is called the internal energy of the body or system. The concept of heat refers to the energy transferred from or to a body or through it when there is a difference in temperature, and heat is measured in joules (J). On the other hand, temperature is a quantitative description of how hot or cold a body or system is. It represents the average kinetic energy of the particles of that body or system, and its international unit is the kelvin (K). To find the value of temperature in kelvins corresponding to its value in degrees Celsius, the relationship (T = 273 + °C) is used, knowing that an increase in temperature by one degree Celsius (°C) is equivalent to an increase of one kelvin (K). When a body or system gains a quantity of thermal energy, the amplitude of the vibrations of the particles increases, as well as their kinetic energy, and thus its temperature rises. The question here is: Do units of mass (1 kg) of different materials require the same amount of heat to raise the temperature of each by one kelvin? When thermal energy increases, the particles of the material move faster Specific heat (c) Specific heat (c) is the amount of heat that a substance gains. The specific heat of a substance is the amount of heat required to raise the temperature of 1 kg of the substance by 1 K. The specific heat of materials varies; for example, the specific heat of aluminum is higher than that of glass. The specific heats of some materials are as follows: Material Specific heat Material Specific heat j/Kg.K j/Kg.K Zinc 388 Lead 130 Murcury ( liquid) 140 Copper 385 Alminum 897 Methanol 2450 Glass 840 Water vapour 2020 Carbon 710 Water 4180 Iron 540 Ice 2060 the amount of heat gained or lost by a body can be calculated using the formula: Q = mcΔT where ΔT is the change in temperature of the body, and m is the mass of the body. Calculate the amount of heat required to raise the temperature of 0.3 kg of copper from 20 degrees Celsius to 70 degrees Celsius, knowing that the specific heat of copper is 385 J/kg.K. Solution: …………………………………………………………………………………………… ……………………………………………………………………………………………  Example: A piece of aluminum weighing 200 g and at a temperature of 80°C is placed in a quantity of water at room temperature. If the final temperature of the system becomes 40°C, calculate the amount of heat gained by the water, knowing that the specific heat of aluminum is 897 J/kg.K. Solution: According to the law of conservation of energy, the amount of heat gained by the water equals the amount of heat lost by the piece of aluminum, assuming no heat energy escapes from the system. Use SI units. The negative sign here indicates that the aluminum piece has lost a quantity of heat to gain it from the water sample, and therefore the amount of heat transferred to the water is 7200j Importance of the high specific heat of water: The specific heat of water is high compared to other materials, approximately equal to 4200 kg K due to the hydrogen bonds between its molecules, which makes it partially responsible for moderating the climate near large bodies of water. The temperature of a large water body during the summer season is lower compared to the temperature of sand and beach rocks. The air above the water surface heats up, causing its density to decrease and rise. The cold air from above the water surface moves towards the land and is called the sea breeze, replacing the hot air that has risen, as illustrated in the figure.. Analytical Activity Analyze the data shown in the table and then answer the following questions: 1) What factors does the specific heat of a substance depend on? 2) Which of the three states of water has the highest specific heat value? Substance Temperature State Physical specific heat (c) Air 25oC Gas 1003.5 Lead 25oC Solid 129 Pure water 25oC Liquid 4181.3 Water vapour 100oC Gas 2020 Ice 0oC Solid 2029 The effect of temperature changes on marine organisms Temperature changes in the oceans affect the distribution of marine organisms. Organisms that live in warm surface waters may be unable to survive in cold depths. For example, coral reefs require specific temperature ranges to survive, and temperature changes due to climate change may lead to their death. The high specific heat of water plays a significant role in the relative stability of water temperatures in seas and oceans, as water can absorb a large amount of heat without a significant change in its temperature. This makes oceans and lakes massive thermal reservoirs, where water absorbs large amounts of solar energy during the day without a significant increase in temperature, then slowly releases this energy at night, helping to maintain stable temperatures in the surrounding marine environment. This thermal balance is very important for the sustainability of marine life. This property helps protect marine organisms from rapid temperature changes, especially cold-blooded organisms (poikilotherms) that rely on the temperature of their surrounding environment. For this reason, we often find these organisms in the depths of seas and oceans where the temperature is stable. Research and Inquiry Research different sources on how to determine the specific heat of water using a Joule calorimeter. 1. In light of the difference in specific heat between land and seawater, explain the phenomenon of sea breeze. 2. Explain why the specific heat of water is a crucial factor in the sustainability of marine life. 3. What factors does the amount of heat lost or gained depend on when the temperature of a substance changes? 1-5 The Effect of Light and Solar Radiation on Marine Environments Imagine diving into the sea, and noticing how the intensity of light changes as you dive deeper into the water. You may have wondered how does this affect the living organisms that inhabit the depths? Solar radiation and light in the water are not merely aesthetic factors; they play a vital role in the lives of marine organisms. How does light in the different layers of water affect photosynthesis? What is the role of solar radiation in maintaining ecological balance in the oceans? Solar radiation refers to the energy produced by the sun, some of which reaches the Earth. It represents the primary source of energy for most processes in the atmosphere, hydrosphere, and biosphere. Through various technologies, solar radiation can be converted into other forms of energy, such as heat and electricity. The technical and economic feasibility of these technologies depends on the available solar resources. Visible light (spectrum) is part of the electromagnetic spectrum, which spreads in the form of electromagnetic waves that differ in wavelength and frequency. Visible light represents a small part of this spectrum and consists of different wavelengths known as the colors of the spectrum (red, orange, yellow, green, blue, indigo, and violet). Classification of solar radiation that reach to the Earth The solar radiation that reaches the Earth can be classified into two categories: Direct solar radiation: This is the radiation that reaches the Earth's surface without scattering before arriving. Indirect radiation: This is the light that is scattered while passing through the atmosphere. The amount of solar radiation that reaches a location or object on the Earth's surface depends on several factors, including geographic location, season, time of day, cloud cover, and elevation above sea level. Solar radiation and its effect on water: Solar radiation is the primary source of energy on Earth and directly affects the various layers of water. When sunlight penetrates the water's surface, part of it is absorbed by the water, suspended materials, and aquatic plants, while the other part scatters in the depths. Light zones in water: As the depth of the water increases, the intensity of light gradually decreases. This light gradient determines different zones in the oceans, such as the illuminated zone (surface), the twilight zone (mid-depth), and the dark zone (depths). Marine organisms live in each of these zones according to their ability to adapt to the available light levels. When sunlight falls on the ocean water, the surface of the water reflects some of it back into the atmosphere. The amount of energy that penetrates the surface of the water depends on the angle at which sunlight strikes the water's surface. The amount of light that penetrates the water surface is large when sunlight strikes it perpendicularly, while the amount of light that penetrates the water surface decreases when sunlight strikes at an angle. Water absorbs almost all the energy of infrared rays from sunlight at a depth of 10 centimeters from the surface. ❖ The depth of the water not only affects the absorption of colors of light but also affects the intensity of light, as the intensity of light gradually decreases as it travels. At a depth of 10 meters, water absorbs more than 50% of the energy of visible light. Even in clear tropical waters, only about 19% of visible light—mostly in the blue range—reaches a depth of 100 meters. Light penetration in the open ocean Light penetration in coastal waters. This illustrative figure shows the difference between light penetration in shallow coastal waters and in the open ocean. When different colors of the spectrum penetrate ocean water, the water absorbs warm colors, such as red and orange (which have longer wavelengths), and scatters cooler colors (which have shorter wavelengths).  Photosynthesis in Aquatic Environments Many autotrophic organisms, such as aquatic plants, algae, and phytoplankton, rely on the process of photosynthesis to convert solar energy into chemical energy used in building the organic materials necessary for growth and survival. This process heavily depends on the availability of light, and thus occurs mainly in the surface layers of water bodies, where light can reach these organisms. Solar Radiation and Ecological Balance Solar radiation is a vital factor in maintaining ecological balance in aquatic environments. It not only affects the photosynthesis process, which is fundamental for marine life, but it also directly impacts water temperature and the distribution of marine organisms. The Effect of Solar Radiation on Ecological Balance in Aquatic Environments The Role of SolaR RadiaTion in The diSTRibuTion of MaRine oRganiSMS Marine organisms are unevenly distributed in the water according to their light and energy needs. Organisms that rely on photosynthesis, such as algae and phytoplankton, are abundant in the surface layers of water where solar radiation is plentiful. For example, coral reefs thrive in warm, shallow waters near the equator where solar radiation is available year-round. This radiation stimulates the growth of symbiotic algae that live within coral tissues and provide it with food. The effecT of SolaR RadiaTion on WaTeR TeMpeRaTuReS: Solar radiation directly affects water temperatures, which in turn influences the distribution of marine organisms. The warm waters resulting from solar radiation in tropical regions attract certain species of fish and marine animals that require specific temperatures to survive and reproduce. For example, tropical fish like tuna and barracuda live in warm waters, while other species like cod prefer the cold waters found in areas farther from the equator. Changes in Solar Radiation Intensity Changes in solar radiation intensity due to seasonal changes or climate change can lead to disturbances in the ecological balance. For example, in polar regions where solar radiation is low or absent during winter periods, photosynthesis rates significantly decrease, affecting the availability of food for marine organisms. This can lead to a decline in the numbers of organisms that rely on photosynthesis, thus impacting the entire food chain. On the other hand, global warming causes water temperatures to rise, leading to coral reef death, which significantly affects marine organisms that depend on them. Effects of Solar Radiation on Ocean Currents Solar radiation also contributes to the formation of ocean currents, which play a key role in the distribution of heat and nutrients in the oceans. These currents affect the distribution of marine life and make some areas rich in food resources. For example, the ( Gulf Stream ) carries warm water from the equator toward the North Atlantic, leading to a temperate climate in areas like Western Europe and enhancing marine biodiversity there. ReSeaRch and inveSTigaTion Measuring Light Intensity in Water objecTive: The student tests the light intensity in water at different depths. ToolS: Light intensity meter, large water tank, multiple light sources, ruler. 1. Place the light source above the water tank. 2. Use the light intensity meter to measure light intensity at different depths. 3. Record the results and discuss the effect of depth on light intensity. check youR undeRSTanding 1. How does the light gradient affect the distribution of marine organisms at ocean depths? 2. Why is the process of photosynthesis important for maintaining ecological balance in the oceans? 1-6 The effecT of hydRoSTaTic pReSSuRe on living oRganiSMS Organisms in the depths of the oceans face a harsh environment that requires unique adaptations for survival, including living under immense water pressure. How does hydrostatic pressure affect living organisms in the depths of water? And how do these physiological adaptations help these organisms survive under such immense pressure? Fluids are materials characterized by their ability to flow, including liquids and gases. While gases are easily compressible and occupy any space they are in, liquids resist compression and thus maintain a nearly constant volume. Pressure at a point in a static liquid Liquids exert pressure. At any point within it, the pressure equals the weight of the column of liquid above that point acting on the unit area around that point. If there is a body at that point, it is affected by a force due to this pressure, which is perpendicular to its surface. The compressive force on a body, measured in newtons, is calculated from its presence in the liquid using the relationship F = P × A, where P is the pre ssure at that point in N/m² and A is the surface area in m² exposed to that pressure. The pressure of a liquid (P) at a point in its interior located at a depth (h) is calculated using the equation Pliquid = p x g x h, where p is the density of the liquid in kg/m³ and g is the acceleration due to gravity in m/s². If the surface is exposed to atmospheric pressure (Pa), then the total pressure acting on the point is: Pa = Pa + Pliquid = Pa + pgh. facToRS affecTing The value of liquid pReSSuRe aT a poinT in iTS inTeRioR: From the above, we conclude that: 1- The pressure of the liquid (P) at a point in its interior increases with the depth of that point (h) below the surface of the same liquid 2- The pressure also increases with the density of the liquid Pressure is measured in units of (N/m²) , which is equivalent to the Pascal (Pascal). In practical fields, a larger unit is used, which is the bar (Bar). 1 Bar = 105 Pascal = 105 N/m². Among the properties of liquid pressure: 1. The pressure at a point within a liquid acts equally in all directions. If the pressure at a certain point in a specific direction is (P), then the pressure in any other direction at that point is also (P). All points located in a horizontal plane in a stationary homogeneous liquid have equal pressure. This explains the property of the surface of connected vessels , where the liquid rises in connected vessels to the same horizontal level regardless of their shape or cross-section. It also explains why the water level in connected seas and oceans takes the same horizontal level. The horizontal level of the sea surface is taken as a reference level and is called "Sea Level" to measure elevations around the globe. exaMple: The base of a fish tank has an area of 1000 cm², and the tank contains water weighing 4000 N. What is the pressure of the water on the bottom of the tank? Solution: Pressure (P) = Weight (W) / Area (A) = 4000 N / (1000 × 10-4 m²) = 4 × 104 N/m² exaMple 2 Calculate the total pressure acting on a swimmer at a depth of 10 meters from the surface of a lake if the density of water is 1000 kg/m³, the acceleration due to gravity is 10 m/s², and the atmospheric pressure at the surface of the lake is 1.013 × 10⁵ N/m². Solution P = P a+ P liquid = Pa + ρgh = 1.013 × 10⁵ + (1000 × 10 × 10) = 2.013 × 10⁵ N/m²  hydRoSTaTic pReSSuRe Hydrostatic pressure is the pressure exerted by water on any object beneath the water surface. This pressure increases as depth increases due to the increased weight of water above the object. At sea level, the pressure equals atmospheric pressure and is approximately 1.013 × 10⁵ N/m², and the water pressure increases by about one atmosphere for every 10 meters below the surface. For example, at a depth of 100 meters, the pressure caused by water will be about 10 times the atmospheric pressure. In the depths of the seas, the pressure is unimaginable; however, many organisms can adapt to the high water pressure. The effect of pressure on the biological adaptations of marine organisms First: Swim bladder Surface organisms, which live near the surface of the water, experience relatively low hydrostatic pressure, and therefore their physical structure is less robust compared to organisms that live in the depths. Organisms in intermediate depths: At depths of 200 to 1000 meters, such as in organisms are more specialized to deal with the increasing pressure. For example, some fish have swim bladders filled with gas that help them control their buoyancy and balance in the water, such as tilapia, or they can transition between different depths during their migration between seas and rivers like salmon. Creatures in deep depths (greater than 2000 meters) experience very high water pressure. Organisms that live in these environments often have compact body structures and protein components and internal fluids that withstand high pressure. Additionally, some of these organisms do not have gas bladders to ensure they do not collapse under this pressure, such as the ray fish (which increase their body density to withstand high pressure). Or they have a bladder containing fluids instead of gases and rely on a large liver rich in oils to increase their buoyancy and control their depth. Secondly: SkeleTal and caRTilaginouS STRucTuReS Bony fish, such as tilapia and mullet, are characterized by having a skeleton made of bones. This provides strong support for the fish's body and stability under various pressures, such as water movement or water pressure. Cartilaginous fish, such as sharks and rays, are a group of fish characterized by having a cartilaginous structure instead of a bony skeleton. Cartilage is a more flexible and lighter tissue compared to bones, which gives cartilaginous fish flexibility that distinguishes them from bony fish. ThiRdly: cellulaR MeMbRaneS The cellular membranes of deep-sea organisms are characterized by the presence of lipoproteins that enhance membrane flexibility and prevent collapse. These proteins reduce the impact of pressure on cellular membranes, preventing damage to cells and ensuring the continuation of vital functions. Check your understanding. 1. How does light gradient affect the distribution of marine organisms in the depths of the ocean? 2. Why is the process of photosynthesis important for maintaining ecological balance in the oceans?  1-7 The Role of SoluTionS and concenTRaTionS in WaTeR MoveMenT and diSTRibuTion of living oRganiSMS Prepare Have you ever wondered why the distribution of living organisms in oceans and lakes differs? How do the concentrations of dissolved substances in water affect the properties of water and the movement of water and distribution of marine organisms? Water in water bodies is not pure; it is a mixture with several dissolved or suspended substances. These substances directly affect the density of water, leading to changes in water stratification and the distribution of living organisms at different depths. 1. aqueouS SoluTionS A solution is a homogeneous mixture of a solvent and a solute. In the aquatic environment, water is usually the solvent, while the solute can be a chemical substance such as salts or other materials. Concentration is the amount of solute in a specific volume of solvent. 2-The effecT of concenTRaTion on WaTeR denSiTy: As the concentration of dissolved substances in water increases, the density of the water increases. These changes in density can lead to different movements of water, such as vertical currents that carry living organisms to different depths or to the surface. 3-colligaTive pRopeRTieS of WaTeR: These are properties of the solution that depend on the number of solute particles, not on their type. The colligative properties include vapor pressure, boiling point, freezing point, and osmotic pressure. a- vapoR pReSSuRe of The liquid: When a liquid and its vapor are in a state of dynamic equilibrium, the vapor formed above the surface of the liquid from the evaporation process exerts pressure on the surface of the liquid called the vapor pressure of the liquid. In pure water solute the surface water molecules are capable of escaping and turning into vapor. There are attractive forces between water molecules, in addition to the attraction caused by the hydrogen bond due to the polarity of the water molecule. In solutions, water molecules are strongly attracted to solute molecules, which reduces the likelihood of water molecules evaporating. The attractive forces between solute molecules and water molecules are stronger than the attractive forces between water molecules themselves, thus decreasing the number of water molecules that can evaporate, and lowering the vapor pressure of the liquid. The decrease in the vapor pressure of the solution corresponds directly to the number of solute molecules or ions in the solution. b- boiling poinT: A liquid boils when its vapor pressure reaches the value of the atmospheric pressure at the surface of the liquid. Therefore, the boiling point of pure liquid under normal atmospheric pressure is constant, and thus it is a property from which the purity of liquids can be inferred. The boiling point of the liquid varies if the atmospheric pressure acting on the surface of the liquid changes. The boiling point of pure liquid increases with an increase in the atmospheric pressure affecting its surface. The boiling point of a solution is higher than the boiling point of pure water at normal atmospheric pressure due to the attractive forces between solute and solvent molecules, which increases the energy required to vaporize the liquid. The increase in the boiling point of the solution corresponds directly to the number of dissolved molecules or ions in the solution. Practical Applications: Can pure water boil at a temperature lower than 100°C? What do you expect the boiling point of pure water to be in the following cases: 1 - At the peak of a high mountain? 2 - Inside a pressure cooker? Exploratory Activity Measuring the dominance degree of several solutions of different salts in pure water with the same concentration, such as sodium chloride solution and sodium bicarbonate solution. ThiRdly: fReezing poinT: The freezing point of the solution is always lower than the freezing point of pure water because the attractive forces between the water molecules and the solute molecules hinder the freezing process and prevent the liquid water from turning into ice crystals. Practical Applications Salt is spread on roads in cold areas after rainfall so that the rainwater turns into a saline solution, thus lowering its freezing point compared to that of water. Consequently, the amount of ice formed on the roads decreases, reducing the chances of accidents. Scientific Activity Measuring the freezing point of several solutions, all with the same concentration of different salts: sodium chloride, calcium chloride, magnesium sulfate. diSTRibuTion of living oRganiSMS in aquaTic enviRonMenTS baSed on concenTRaTion Some living organisms adapt to certain concentrations of dissolved substances. For example, marine organisms that live at great depths adapt to the high densities of water due to the high concentrations of salts. The distribution of living organisms in aquatic environments is affected by the following factors: 1. Water availability Freshwater versus saltwater; living organisms are distributed based on the type of water. For example, freshwater fish cannot survive in saltwater, and vice versa. 2- Osmotic adaptations Living organisms require specific adaptations according to the concentration of salts in their environment and osmotic pressure balance. Marine organisms adapt to high salt levels, while freshwater organisms adapt to avoid excessive water absorption, as illustrated in the figure. 3-Nutrient and pollutant concentrations The concentration of nutrients and pollutants affects the diversity of living organisms. Resource-rich environments support greater diversity, while polluted environments may lead to decreased diversity. 4- Seasonal changes The different seasons affect water availability, which in turn affects the distribution of living organisms. For example, certain species may migrate to new areas during droughts or floods. 5- Water currents Variations in water bodies affect the distribution of oxygen and nutrients, impacting the gathering and feeding areas of living organisms. Check your understanding 1- How do dissolved substance concentrations affect water density? 2- What is the relationship between dissolved substance concentrations and water current movement? 3- How do chemical solutions in water affect the distribution of marine organisms? 1-8 The inTeR balance and The Role of huManS in aquaTic life How human activities can affect aquatic ecosystems? Human activities play a significant role in impacting aquatic life, from overfishing to pollution. Here, we will explore how ecological balance maintains the health of marine environments, how human activities can lead to changes in this balance, and we will learn about strategies to protect and sustain these systems. The Importance of Ecological Balance in Aquatic Systems Ecological balance is a state of dynamic stability that occurs when living organisms in an ecosystem interact in a way that preserves the continuity of life. This balance involves maintaining nutrient balance, biodiversity, and energy flow through food webs. 1- Nutrient balance in aquatic systems such as lakes and rivers must have a balance in nutrient levels such as nitrogen and phosphorus. These elements are essential for the growth of plants and algae that form the foundation of the food chain. If nutrient levels increase excessively, it can lead to an unnatural algal bloom.  2- The balance between living organisms in aquatic systems involves each species interacting with others in multiple ways, either as prey or predators over resources. The presence of predatory fish in the aquatic ecosystem helps maintain the balance of prey fish and other organisms. For example, in a marine environment with different fish species, if the numbers of predatory fish decline due to overfishing, the number of small fish may increase excessively, leading to an unbalanced consumption of food resources and a disruption in the ecosystem. 3- The flow of energy through the food web in the aquatic ecosystem energy start flowing from producers (such as algae and plants that perform photosynthesis) to consumers (such as herbivorous and predatory fish). This natural flow of energy helps regulate the populations of organisms at each level of the food chain. For example, if small fish that feed on zooplankton are consumed in large quantities by predatory fish, it leads to an increase in zooplankton populations, which affects the growth of algae, and consequently disrupts the balance in the system. Ecological balance in aquatic systems: Coral reefs and the marine ecosystem provide a habitat for many marine organisms. Predatory fish help maintain the balance of coral reefs by controlling the populations of smaller organisms like sea urchins, which can destroy the reefs if their numbers increase unnaturally. ❖ Impact of human activities on aquatic life: Have you ever thought about how human activities can affect aquatic ecosystems? Human activities play a significant role in impacting aquatic life, from overfishing to pollution. polluTion Chemical pollution such as pesticides and heavy metals that are discharged into the water, can affect water quality and harm the health of living organisms. oveRfiShing can lead to a decline in the populations of certain species and affect ecological balance Environmental destruction is the destruction of natural habitats such as coral reefs and wetlands Loss is caused biodiversity.  The role of humans in maintaining ecological balance. Humans are considered a significant factor in the changes that occur in the environment, whether positive or negative. Therefore, they must take responsibility for maintaining ecological balance and taking necessary measures to reduce negative impacts. Here are some roles that humans can play in maintaining ecological balance: 1. conSeRvaTion of naTuRal ReSouRceS: Humans should handle natural resources such as water, forests, soil, and wildlife with care. This can be achieved by using resources sustainably, avoiding pollution, and preventing waste. 2. enviRonMenTal aWaReneSS and educaTion: Humans should learn and understand the impact of their actions on the environment and share this knowledge with others. This can be achieved through awareness and environmental education activities, such as media campaigns, workshops, and school education. 3. SuSTainable developMenT: Maintaining ecological balance requires adopting sustainable development models that meet the needs of the current generation without compromising the ability of future generations to meet their own needs. Humans should strive to develop and use clean and sustainable technologies, promote sustainable agriculture, and enhance sustainability in industrial and urban sectors. 4. paRTicipaTion in enviRonMenTal policieS: Humans should actively participate in environmental decision-making and in the development and implementation of environmental policies. This can be done through participating in public dialogues and forums, engaging in environmental organizations, and pressuring governments to take strong actions to protect the environment. 5. TRanSiTion To eco-fRiendly pRacTiceS: Humans can take small steps in their daily lives to contribute to maintaining ecological balance, such as reducing water and energy consumption, sorting waste, and using public transportation or bicycles for commuting. Research and Investigation Goal: Developing a Plan to Protect Aquatic Ecosystems Objective: Develop a plan to protect ecosystems from degradation. Tools: Worksheets with information on protection strategies. Steps: In this activity, you will learn how to protect aquatic ecosystems that are an important part of our planet. First, you will choose a specific aquatic ecosystem, such as a river, lake, or ocean. Then, you will review the challenges faced by this system, such as pollution, climate change, or overexploitation of resources. Finally, you will design a comprehensive plan to protect this ecosystem, including specific actions and strategies you can implement to safeguard it from degradation. You will use the worksheets provided to gather information and document your plan in detail. you can STudy The folloWing exaMple: The Nile River is the backbone of life in Egypt, where millions rely on its water for agriculture, drinking, and fishing. However, the river faces significant challenges threatening its sustainability, including industrial pollution, over-extraction of water, and the impacts of climate change. Urgent actions must be taken to protect this vital ecosystem and ensure its sustainability for future generations.  Research Questions ❖ Industrial Pollution: 1. What are the main sources of industrial pollution in the Nile River? 2. How does industrial pollution affect water quality and aquatic life in the Nile River? 3. What possible measures can be taken to reduce industrial pollution in the Nile River? 4. Are there successful examples from other countries in reducing industrial pollution in their rivers? How can they be applied in Egypt? ❖ Overexploitation of Water Resources 1. How does the overexploitation of water affect the water level of the Nile River? 2. What modern agricultural techniques can be used to reduce water consumption in agriculture? 3. What is the impact of dams and water diversion projects on the flow of the Nile River? 4. How can water consumption be regulated among different users (agriculture, industry, population) to ensure the sustainability of water resources?  ❖ Climate Change 1. How does climate change affect the Nile River in terms of water flow, drought, and flooding? 2. What climate changes are expected in Egypt over the coming decades, and how will they affect the Nile River? 3. What possible strategies are there for adapting to the impacts of climate change on the Nile River? 4. How can technology be used to develop early warning systems for floods and droughts in the Nile River? ❖ Ecosystem Protection: 1. What animal and plant species are endangered in the Nile River due to current environmental challenges? 2. How can environmental awareness among the local community be enhanced to participate in efforts to protect the Nile River? 3. What are the current government policies for protecting the Nile River, and are they sufficient? 4. How can the local community and non-governmental organizations be involved in efforts to protect the Nile River?  Chapter 2 Atmosphere  Chapter Two: The Atmosphere Learning Outcomes Upon completing the study of this chapter, the student will be able to: 1. Explain the structure of the atmosphere and its main components and their effects on the Earth's surface. 2. Distinguish between the different layers of the atmosphere and describe the characteristics of each layer. 3. Analyze the impact of physical factors in the atmosphere, such as temperature, pressure, humidity, solar radiation, and wind speed on the distribution of living organisms and climatic conditions. 4. Compare the effects of various physical factors on climate in different geographical areas. 5. Evaluate the impact of chemical interactions in the atmosphere, such as ozone formation and air pollution, on public health and the environment. 6. Explain how chemical interactions in the atmosphere affect air quality and climate change. 7. Integrate the acquired knowledge to assess the practical effects of changes in the atmosphere on daily life and the environment. 8. Propose practical solutions to air pollution and climate change problems based on the information learned. Issues Involved 1. Climate Change 2. Air Pollution 3. Resource Sustainability  Lesson1 The Atmosphere It's a layer of mixture of gases that surround the earth planet. - It protects the earth from outer harmful rays and rocks coming from outer space. - it adjusts the temperature of the earth. -its gaseous mixture provides the existence of life on earth. -its steadiness due to gravity what will happen if the planet doesn't surround by atmosphere. Mercury has no atmosphere. So its temperature increases with great value due to absorption of sunlight and when sun goes the planet loses its heat very fast during its rotation. Bec. It doesn't contain atmosphere Components of Atmosphere: 1-Nitrogen N2: it occupies 78% from volume of atmosphere. -it's slightly inactive bec. It's difficulty react with the other gases or elements except under certain conditions of high temperature or lightening So its oxides are rarely formed. 2-Oxygen O2: it occupies 21% of volume of atmosphere. -It’s very important in respiration and combustion. -It's an active gas in most of chemical reactions. 3-Argon gas Ar: inert gas occupies 0.93% 4- Carbon dioxide CO2: it occupies 0.04% and it's important in photosynthesis process. 5-Watervapour H2O: its volume differs from place to another in the surface near area and plays an important role in weather phenomena and climatic changes. 6- Ozone gas O3: -it exists at 10 - 55 km from sea level (earth surface) Atmospheric Layers: 1- troposphere 2-stratosphere 3-mesosphere 4- Iono sphere 1-troposphere -It's the nearest layer to earth's surface. -its thickness is 18 km at equator and 8 km at the two poles. Give reason: Increase thickness of troposphere at Equator? Due to convection currents that carry and push the warm less dense air upward. -By increasing height the temp. decreases with one degree each 176 meter due to decrease in atmospheric pressure as air molecules expand and need energy from kinetic energy of the air molecules. -Most weather phenomena occur in this layer. As clouds, rains and wind currents. Atmospheric pressure: It's the weight of air column on unit area Change of atmospheric pressure with change in height above sea level What is the effect of rising up above sea level on the air density? The air pressure decrease from sea level to increase the length (weight) column of air. Isobar: - It is the curved lines that join the points of equal pressure in atmospheric pressure maps. - the wind moves from the areas of high atmospheric pressure to the areas of low atmospheric pressure.so wind direction is vertical. -The Centre of low atm. pressure areas is represented by L -The Centre of high atm. pressure areas is represented by H -Tool used to measure atmospheric pressure: BAROMETER and its unit bar and millibar Normal atmospheric pressure is: 1013 mb It measured at the sea level and it equals 760 mm Hg Also it euals 101300 N/m2 2- stratosphere Stratosphere is the second atmospheric layer, which is also called ( Ozone layer) -its height is 50 Km above the sea level. -Ozone layer is formed in this layer by effect of UV. -temperature doesn't change in stratospheretill20 km so wind direction is horizontal so pilots prefer to fly their aero planes in lower part. Then temp. begins to increase due to presence of ozone gas in upper part.  3-Meso sphere -its thickness reaches 30 km -Temp. decreases till -90oC -Asteroids burn in this layer before reaching earth surface. 4-Ionosphere - It extends to 640 km above the sea level It contains charged ions due to ionization Of atoms of atmosphere. It used in wireless communication for long Distances Bec.it can reflects radio waves Check your understanding  Exercise Q1-Choose the correct answer: 1- Ozone gas exists in ………..layer. a- troposphere b- stratosphere c- mesosphere d- ionosphere 2- Most of weather phenomena occur in ….. layer. a- meso sphere b- ionosphere c- troposphere d- stratosphere 3- ………….layer is used in wireless communication. a- meso sphere b- ionosphere c- troposphere d- stratosphere Q2:mention the importance of atmosphere? …………………………………………………………………… Q3:How to protect ozone layer? ……………………………………………………………………  Lesson 2-2 Physical Factors in the Atmosphere The atmosphere is a dynamic system in which several physical factors interact, affecting weather and climate, and consequently the distribution of living organisms in various climatic regions. How do we explain the change in weather from day to day? Or why are some areas warm and sunny while others are cold and dry? In this lesson, we learn about the impact of various physical factors such as heat, pressure, humidity, solar radiation, and wind speed on our daily lives and on living organisms. **Physical Factors and Their Impact on the Atmosphere:** First: Heat: Heat is considered one of the most important climatic factors because it affects other factors such as atmospheric pressure, winds, humidity, condensation, and consequently rainfall. The primary source of heat and light on Earth is the sun. When sunlight reaches the Earth, it heats the surface of the land and water more significantly, and then the heat is transferred to the gaseous atmosphere surrounding the Earth. The temperature begins to rise, and the layers of the atmosphere close to the Earth's surface are warmer than those farther away. Sunlight does not heat all areas of the Earth's surface at the same rate; areas where sunlight strikes vertically or nearly vertically receive a greater amount of thermal energy per unit area than those where sunlight strikes at an angle.  ❖ Air temperature measurement Meteorological agencies measure air temperature periodically, comparing it with temperatures in other areas and also with temperatures recorded in previous years during the same climatic season. These agencies use one of the following measuring instruments: 1 - Celsius scale ( Co ) , which is the scale used in Egypt, for example. 2 - Fahrenheit scale ( Fo ), which is the scale used in the United States of America, - Kelvin scale (TK), which represents the absolute temperature scale used in scientific fields. The relationship between temperature scales The relationship between the absolute temperature scale TK and the Celsius scale tc: Tk = tc + 273 The relationship between the Fahrenheit temperature scale tF and the Celsius scale tc: tF = (9/5 x tc) + 32 Training Find the value of the freezing point of pure water and its boiling point on the Kelvin and Fahrenheit scales, and record it in the corresponding table. Temperature tc tF TK Pure water 0o freezing point Pure water 100o boiling point Heat Transfer Mechanisms. heat Is generally transferred In three ways: 1. Conduction: Heat is transferred in a solid body or between two touching bodies, moving from particles in the region of higher temperature to adjacent particles in areas of lower temperatures without the transfer of those particles. Some materials are characterized by good thermal conductivity, such as metals, while others have low thermal conductivity, like wood.  2. Convection: Heat is transferred through fluids by convection, where the density of the hotter parts of the fluid is less than that of the cooler parts, causing the less dense hotter parts to rise and be replaced by denser parts. Have you ever seen a bird soaring high without flapping its wings? This is not just a beautiful sight, but a result of birds exploiting what is known as thermal soaring. Thermal soaring is a technique used by birds to stay in the air for long periods without needing to continuously flap their wings, thus conserving energy. The bird glides over rising warm air currents through convection, maintaining its altitude. 3. Radiation: Heat is transferred in the form of electromagnetic radiation. Thermal radiation spreads in all directions without the need for a physical medium. It can propagate in a vacuum and through gases as well.  Research Activity In collaboration with your colleague, draw a diagram showing the ways heat transfers from the sun to the Earth's surface and then to the atmosphere. Which materials are considered the best in terms of thermal conductivity for use in making cooking pots to save energy used in heating? Are there other factors that influence your choice in finding the best cooking pots? Secondly: Atmospheric Pressure: r4r Atmospheric pressure affects weather and climate. In areas of low pressure, the weather is usually stormy and rainy, while the weather in high-pressure areas is stable and dry. North Pole The difference in atmospheric Polar wind pressure causes winds to blow. At Head wind the equator, warm equatorial Commercial wind air rises in the atmosphere, equator creating a low-pressure area. At Commercial wind the same time, cooler and denser Head wind air moves from the surface toward Polar wind North Pole the equator to replace the warm air. Generally, this movement is from high-pressure areas to low-pressure areas. There are several wind systems at the Earth's surface, including polar winds, which are dry and cold winds blowing from high-pressure areas around the North and South Poles to low-pressure areas in the subpolar regions. Atmospheric pressure also affects the amount of oxygen available for breathing. In areas of low atmospheric pressure, such as high altitudes, the levels of oxygen available in the air are lower, requiring adaptations from living organisms that thrive in low-pressure environments. in those areas, such as the increased number of red blood cells. Mountain climbers may suffer from the rupture of tiny blood vessels in the nose due to the significant difference between the blood pressure inside them and the low atmospheric pressure outside. Third: Humidity Humidity is the amount of water vapor present in the air. High humidity levels in tropical areas affect cloud formation and rainfall, where rain is abundant and supports the growth of dense forests. Its percentage depends on temperature and pressure; the higher the air temperature, the greater the amount of water vapor it can hold. When the air contains the maximum amount of water vapor it can hold at a specific temperature and pressure, it is said to be saturated with water vapor. The humidity level in the air is measured by a hygrometer.  The effect of humidity on living organisms: Some vital processes in living organisms are affected by the humidity level in the surrounding air. As the relative humidity of the air around the plant increases, the rate of transpiration decreases, which reduces the rate of water and salts being lifted from the roots to the leaves. In animals, the rate of sweat evaporation decreases, reducing the efficiency of cooling their body High humidity Low humidity Water molecules in the atmosphere surrounding the leaf Water vapor molecules in Water vapor atmosphere molecules in the air  Fourth: Wind Speed The movement of air from areas of high atmospheric pressure to areas of low atmospheric pressure. Winds affect the distribution of heat and humidity in the atmosphere, which in turn affects the climate in different regions. Strong winds can lead to significant changes in weather. The Impact of Climate Factors on Living Organisms 1-Cactus The cactus adapts to desert conditions of water scarcity and low humidity by storing water in its stem and developing spines to reduce water loss. 2- Pine trees Pine trees adapt to cold climates through the shape of their needle-like leaves, which reduces water loss in icy conditions. 3- The penguin The penguin adapts to the cold climate of Antarctica thanks to a thick layer of fat and a feather coat that retains heat. 4- The camel The camel adapts to the desert environment by being able to withstand high temperatures and water loss, and it can drink large amounts of water in a short time. 5- Migratory birds Migratory birds adapt to climate changes by migrating to warmer areas in winter in search of food and moderate temperatures. 6- The octopus The octopus adapts to different marine environments by changing its colors and shape to hide from predators. 7- The starfish The starfish adapts to the oceans through its ability to survive in various temperature and salinity conditions. 8- Ants: Ants show various adaptations based on climate, such as building nests underground to avoid heat or cold. Ants build nests underground to adapt to climatic conditions.  Research and Investigation Activity 1: Measuring the Impact of Physical Factors Objective: Understand the impact of physical factors on the atmosphere. Tools: Thermometer, barometer, hygrometer, anemometer. Steps: 1. Measure temperature, pressure, humidity, and wind speed in your area over a full day. 2. Record the data and analyze how changes in these factors affect local weather. Activity 2: Analyzing Weather Data Objective: Analyze weather data to understand the impact of physical factors. Tools: Local or global weather data. Steps: 1. Choose two different geographical regions (such as tropical and polar regions). 2. Compare temperature, pressure, humidity, and wind speed data between the two regions. 3. Analyze how these factors affect the climate in each region.  Check Your Understanding 1. What is the relationship between atmospheric pressure and temperature in the atmosphere? How do physical factors such as heat, pressure, and humidity affect daily weather and long-term climate? Research Activity Using various resources, work with a group of your peers to prepare a presentation on climate change and its impact on local and global ecosystems. Can environmental changes be predicted and adapted to ensure the sustainability of life on Earth? Heat Transfer Mechanisms and Climate Factors Assessment 1. Which of the following is NOT a mechanism of heat transfer? a. Conduction b. Convection c. Radiation d. Evaporation 2. In which heat transfer mechanism does energy move through a material without the movement of particles? a. Radiation b. Convection c. Conduction d. Sublimation 3. What is the primary method of heat transfer in fluids? a. Radiation b. Conduction c. Convection d. Reflection 4. Which of the following best describes thermal radiation? a. Transfer of heat through particle collisions b. Movement of heated particles in a fluid c. Electromagnetic waves that can travel through a vacuum d. Heat transfer only possible in solids 5. Why do birds use thermal soaring? a. To avoid predators b. To conserve energy c. To increase their body temperature d. To find food more easily 6. Which material is generally considered to have good thermal conductivity? a. Wood b. Plastic c. Metal d. Rubber 7. What causes winds to blow? a. Differences in atmospheric pressure b. Earth's rotation c. Differences in humidity d. Changes in ocean currents 8. How does atmospheric pressure typically affect weather in a region? a. Low pressure areas usually have stable, dry weather b. High pressure areas usually have stormy, rainy weather c. Low pressure areas usually have stormy, rainy weather d. Atmospheric pressure has no effect on weather 9. What adaptation do organisms living at high altitudes often develop? a. Larger lung capacity b. Increased number of red blood cells c. Thicker skin d. Enhanced night vision 10. How does humidity affect the rate of transpiration in plants? a. Higher humidity increases transpiration rate b. Higher humidity decreases transpiration rate c. Humidity has no effect on transpiration d. Only temperature affects transpiration 11. Which of the following is used to measure humidity levels in the air? a. Barometer b. Thermometer c. Anemometer d. Hygrometer Lesson 3-2 Chemical Interactions in the Atmosphere The atmosphere is not just a shield protecting the Earth; it is a stage for complex chemical interactions that play a crucial role in our daily lives, from the formation of ozone that protects the Earth from ultraviolet rays to air pollution that threatens the health of humans and other living beings. These chemical interactions in the atmosphere affect air quality, climate, and public health. In this lesson, we will learn how these interactions occur and their impacts on the environment and humans. 1. Ozone Formation The ozone molecule (O3) consists of three oxygen atoms. Ozone is formed in the stratosphere of the atmosphere due to the effect of ultraviolet rays coming from the sun on oxygen molecules (O2), as follows: A. Ultraviolet rays with a wavelength less than 240 nm cause the covalent bond in the oxygen molecule (O2) to break, resulting in two individual oxygen atoms (O). B. The individual oxygen atom combines with an oxygen molecule to form the ozone molecule.  **Importance of Ozone:** Ozone acts as a shield protecting the Earth from harmful ultraviolet rays. Without this layer, life on Earth would be severely damaged due to these rays. The Negative Impact of Ozone in the Troposphere: ❖ Air Pollution: Ozone gas in the troposphere is part of smog. This smog forms as a result of the interaction of ozone, nitrogen oxides (NOx), sulfur dioxide (SO2), and fine particles in the presence of sunlight. ❖ Health Problems: Ozone can cause health issues such as irritation of the eyes, nose, and throat, breathing problems, worsening of asthma, and lung damage. ❖ Environmental Effects: Ozone can damage plants and agricultural crops, affecting their growth and quality. It can also cause the deterioration of materials like plastic and rubber. ❖ Greenhouse Gas Effects: Ozone is considered one of the greenhouse gases in the troposphere that contribute to the greenhouse effect, which can lead to climate changes such as rising temperatures and changes in weather patterns.  2- Air Pollution: Sources of air pollution can be natural, such as volcanoes and wildfires, or human-made, such as factory smoke and vehicle emissions. ❖ Air Pollution and Climate Change: Some air pollutants, like carbon dioxide (CO2) and other greenhouse gases, contribute to the greenhouse effect, leading to significant climate changes such as polar ice melting and rising sea levels. ❖ Air Pollution and Human Health: Air pollution causes many respiratory diseases such as asthma, bronchitis, and allergies, as well as cardiovascular diseases like heart and blood vessel diseases. Exposure to air pollution can affect brain growth and child development. Some pollutants, such as benzene and arsenic, are linked to an increased risk of certain types of cancer.  ❖ Air pollution and ecosystems can lead to the loss of biodiversity in ecosystems. 1. Its effect on plants: Ground-level ozone can burn plant leaves, reducing their ability to photosynthesize. Consequently, it negatively affects plant growth and productivity. 2. Its effect on animals: Birds and insects are affected by air pollution, impacting their behavior and reproduction. For example, the decline in bee populations due to air pollution affects the rate of plant pollination. Strategies to reduce pollution: 1. Use public transportation to reduce car exhaust emissions. 2. Improve energy efficiency: Use energy-efficient technologies in homes and factories. Example: Use LED lights and high-efficiency electrical appliances. 3. Increase green spaces: Plant trees and public gardens to help improve air quality. Research and Investigation Analyzing the impact of pollution on the environment Objective: Understand the impact of air pollution on ecosystems. Tools: Data on air quality in your area, plant samples. Steps: 1. Collect data on air pollution levels in your area over a month. 2. Observe the impact of pollution on local plants (such as leaf damage or color changes). 3. Analyze the relationship between pollution levels and changes in plant health. Choose the correct answer 1- Which of the following chemical reactions is considered one of the main reasons for the formation of ozone in the stratosphere? A) The reaction of nitrogen oxide with carbon dioxide. B) The reaction of oxygen with ultraviolet rays. C) The reaction of water vapor with carbon. D) The reaction of ozone with sulfur oxide. 2- What chemical compound is considered responsible for the formation of smog in major cities as a result of the reaction between nitrogen oxides and hydrocarbons? A) Ozone B) Nitrogen oxide C) Sulfur dioxide D) Carbon dioxide 3- What compound is produced by the reaction of nitrogen oxide with ozone in the atmosphere that contributes to air pollution? A) Nitrous oxide B) Nitric oxide C) Nitrogen dioxide D) Ozone Lesson 4-2 Atmospheric Changes and Their Effects Get Ready The changes occurring in the atmosphere lead to numerous climatic changes. Recently, a rise in summer temperatures has been observed year after year due to the greenhouse effect, with air pollution being the primary cause. Therefore, some scientists predict that if the deterioration of air quality continues at the same rate in the future, living organisms may need to exist within bubbles that protect them from pollution and radiation. In thIs lesson , we will discuss how we can apply the knowledge we have learned about the atmosphere to assess these effects and develop sustainable solutions to environmental problems. Learn Changes in the Atmosphere and Their Impact on Daily Life: Our understanding of the atmosphere helps us recognize the importance of protecting it. Continuous changes in the ratios of gas mixtures in the atmosphere reduce its ability to maintain the Earth's surface at a suitable temperature for the life and activity of living organisms and its ability to protect the Earth from harmful solar radiation. Climate Changes and Their Impact on Ecosystems: A global climate conference is held where governments discuss the changes occurring due to shifts in the climate map and how to mitigate climate change and prepare for it in the future. Among these issues: Global Warming Global warming is defined as the continuous rise in the temperature of the air adjacent to the Earth's surface. Emissions of greenhouse gases result from burning fossil fuels such as coal, oil, and gas. The greenhouse effect acts like a blanket surrounding the Earth, leading to the trapping of heat in the atmosphere and raising temperatures. Global warming causes significant changes in the climate, melting polar ice, and rising sea levels. The greenhouse gases that cause global warming include carbon dioxide, methane, nitrous oxide, chlorofluorocarbons, and water vapor. The greenhouse gases in the atmosphere work on the same principle as a greenhouse, as the atmosphere allows short-wavelength solar radiation to pass through to the Earth, which in turn absorbs this radiation and then re-emits it as long-wavelength thermal radiation. Greenhouse gases significantly prevent this radiation from passing into outer space, leading to a gradual increase in the Earth's surface temperature year after year. **Negative Effects of Global Warming** **Melting Ice: ** A large amount of freshwater is found frozen in glaciers and ice masses at the poles. With the increase in Earth's temperature, ice masses are repeatedly breaking off, threatening coastal flooding and leading to an environmental disaster. Its features include: 1. The extinction of polar organisms due to the destruction of their natural habitat, resulting in a decrease in biodiversity and an imbalance in the ecosystem. 2. The occurrence of severe climate changes, such as hurricanes, floods, droughts, and others. **Solutions to Air Pollution and Climate Change** 1- Expanding the use of renewable energy: Transitioning to clean energy sources such as solar energy, wind energy, and hydropower can reduce greenhouse gas emissions. 2-Afforestation: Have you noticed that the Egyptian state is concerned with having green spaces and gardens in the establishment of new cities? Do you know the reason? The presence of a large amount of vegetation helps to increase the process of photosynthesis carried out by plants, which plays a fundamental role in absorbing carbon dioxide, the main cause of global warming. Therefore, afforestation is one of the most important methods to reduce global warming. How does the Earth retain atmospheric gases? Escape Velocity The molecules of each gas move at tremendous speeds that depend on the mass of the gas molecule and the temperature. Naturally, this speed is greater for lighter molecules at higher temperatures. For any object to escape a planet's gravity, it must gain a certain speed called escape velocity (Ve), which is a constant value for each planet. The escape velocity from Earth's gravity is about 11.2 km/sec. ❖ The retention of a gas on a planet's surface is related to the relationship between the effective speed of the gas molecules (Vrms) and the escape velocity from the surface of that planet (Ve). ❖ If the effective speed of the gas molecules (V) is less than the escape velocity, then the gas molecules cannot escape into space from the planet's gravity, and the planet retains this gas on its surface. ❖ If the effective speed of gas particles is equal to or greater than the escape velocity from the planet's gravity (Verms ≥V), then gas particles can escape the planet's gravity into space. Consequently, this gas becomes rare or nonexistent on the surface of this planet. This applies to planets with low escape velocities, such as Mercury. Have you now concluded why Earth retains its atmosphere? The Impact of Atmospheric Changes on Living Organisms 1 - Changes in Temperature Changes in the atmosphere affect the lives of living organisms. This includes changes in temperature, atmospheric pressure, humidity, and air pollution. Our understanding of how these changes affect daily life enables us to take effective steps to adapt to these changes. 1- Changes in Temperature: Temperatures directly affect the growth of many plants. For example, tomatoes are plants that require certain temperatures to grow well. Increased temperatures may negatively impact the production of certain crops, such as wheat. Therefore, some crops are classified as summer crops and others as winter crops. 2- Changes in Humidity: Some plants, such as tropical plants, require high humidity for their growth, while desert plants thrive better in low humidity. 3- Air Pollution ❖ Air pollution negatively affects human public health and causes many respiratory diseases. ❖ Air pollution affects plants and animals, impacting wildlife, and may lead to the extinction of some species. Research and Investigation Activity1 Developing Projects or Models for Environmental Solutions objeCtIve: Apply scientific knowledge to develop practical solutions for environmental problems. tools: Environmental materials, miniature models, design programs. steps: 1. Choose an environmental problem related to the atmosphere (such as air pollution). 2. Design a model or project that contributes to solving this problem. 3. Present your model with a scientific explanation of how it works and its potential impact. Activity 2: Discussing Real Case Studies objeCtIve: Understand real applications of technologies to mitigate air pollution and climate change. tools: Scientific articles, environmental reports. steps: 1. Choose a case study related to a specific environmental problem. 2. Read the study and extract the main points. 3. Discuss in a group how solutions were applied in this case and how they can be improved. Activity3: Field Visit Visit a weather station or environmental research center to understand how changes in the atmosphere are measured. **Axis One - Ecosystems and Sustainability of Life** Check Your Understanding 1. How do changes in the atmosphere affect daily life? 2. What are some possible solutions to address climate change and air pollution? 3. Why does Earth's gravity retain the atmosphere and not let it escape? Integration of Sciences (Technology and Environmental Sciences) Technology: How do modern technologies contribute to reducing air pollution and improving quality of life? Environmental Sciences: How can we assess the environmental impact of human activities on the atmosphere and provide sustainable solutions? Conclusion The changes occurring in the atmosphere have long-term effects on our lives and on the planet as a whole. By understanding these changes and working to develop practical solutions, we can contribute to protecting the environment and ensuring the sustainability of life for future generations.  Chapter Three Soil Learning Outcome s : Upon completing the study of this chapter, the student will be able to : 1-Describe the composition of soil and its main components such as minerals, organic matter, water, and air. 2-Explain the role of soil in supporting plants and maintaining the balance of the ecosystem. 3-Relate different soil properties to their impact on plant health. 4-Illustrate the effect of acid rain on soil. 5-List soil measurements and explain conservation strategies. 6-Innovate methods to develop soil conservation plans. Issues Involved : 1-Climate change 2-Reducing pollution 3-Environmental conservation 4-Sustainability  Lesson 1-3 Soil Composition and Its Importance in the Ecosystem Why do plants grow well in certain soils while not thriving in others? What makes soil so crucial for supporting plant life? In