Bio Exam - PDF

1. Advantages of Solar Energy Low Maintenance: Think of solar panels as simple, reliable machines that don’t require much attention. They don’t have any moving parts that could break down, so once they’re installed, they need very little maintenance. You may just need to clean them once or twice a...

1. Advantages of Solar Energy Low Maintenance: Think of solar panels as simple, reliable machines that don’t require much attention. They don’t have any moving parts that could break down, so once they’re installed, they need very little maintenance. You may just need to clean them once or twice a year to remove dirt or dust. Transformation of Energy (Solar to Electrical): Solar panels capture sunlight and convert it directly into electricity using something called photovoltaic cells. It’s like having a device that takes the sun’s energy and turns it into power for your home or gadgets. This is how we get “solar power” from sunlight. Store Solar Energy: Imagine solar panels produce electricity during the day when the sun is shining. But what if you need electricity at night? This is where solar batteries come in. They store the energy your panels produce during the day, so you can use it when the sun isn’t out. Eco-Friendly: Solar energy doesn’t produce harmful pollution like burning fossil fuels does. There’s no smoke, no carbon dioxide, and no chemicals released into the air. This makes solar energy a clean and green option, helping the planet by reducing pollution. Renewable: The sun’s energy is limitless. It shines every day, and as long as the sun is there, we can keep using solar energy. Unlike oil or coal, which can run out, the sun provides a continuous, renewable source of energy for the future. 2. Disadvantages of Solar Energy Costly to Start Off: Installing solar panels and all the required equipment can be expensive. However, over time, solar energy can save you money on your electricity bills, but the initial cost might be a barrier for some people. Needs Space: Solar panels need enough space to be effective. If you live in a small house with a small roof, it might be challenging to fit enough panels to generate a significant amount of power. Seasonal: Solar energy relies on sunlight, so if you live in a cloudy or rainy area, or during the winter when days are shorter, the amount of sunlight you receive can be limited. This means solar power can be inconsistent, especially if you’re depending on it for all your energy needs. No Solar Power at Night: Solar panels need sunlight to generate power, so they don’t work at night. If you don’t have a battery to store the energy, you’ll need another power source at night or during cloudy days. 3. Substances that Contribute to Acid Rain Sulfur Dioxide (SO₂): When we burn coal or oil, sulfur in those fuels reacts with oxygen in the air to form sulfur dioxide. This gas mixes with water in the atmosphere and turns into sulfuric acid, which falls as acid rain. Volcanic eruptions also release sulfur dioxide naturally. Nitrogen Oxides (NOₓ): Nitrogen oxides are produced by the burning of fossil fuels in cars, trucks, and factories. These gases combine with water vapor in the air and form nitric acid, which also contributes to acid rain. Carbon Dioxide (CO₂): When carbon dioxide combines with water in the air, it forms a weak acid called carbonic acid. While this is not the main contributor to acid rain, it still adds to the overall acidity of precipitation. Ammonia (NH₃): Ammonia is released from agricultural activities like fertilizers and animal waste. It can react with acids in the air to form compounds that contribute to the acidification of rain. 4. Effects of Acid Rain on the Environment Pollutes Water: Acid rain lowers the pH of lakes, rivers, and streams, making the water more acidic. This can harm aquatic life, such as fish and plants, and disrupt the food chain in these ecosystems. Burns Leaves and Trees: The acidity in rain damages the surface of leaves, which harms the plant’s ability to photosynthesize and absorb nutrients. Over time, this weakens trees, making them more susceptible to disease, drought, and other stresses. Impacts Soil Quality: Acid rain leaches essential nutrients like calcium, magnesium, and potassium from the soil, making it less fertile. This results in poorer soil quality, which makes it harder for plants to grow and thrive. 5. Resources That Contribute to Acid Rain Coal: When coal is burned for energy, it releases sulfur dioxide and nitrogen oxides into the atmosphere, both of which contribute to acid rain. Oil and Gasoline: Cars and power plants burning oil and gasoline release nitrogen oxides, which combine with water vapor in the atmosphere to form acid rain. Natural Gas: While burning natural gas releases fewer pollutants compared to coal and oil, it still emits nitrogen oxides, which contribute to the formation of acid rain. Industrial Processes: Factories that make products like steel, paper, and cement release sulfur dioxide and nitrogen oxides into the air, which can mix with rain and cause acidification. Volcanic Eruptions: Volcanoes release sulfur dioxide and other gases into the atmosphere. While natural, these emissions can contribute to acid rain in nearby areas. Agricultural Activities: The use of fertilizers and animal waste can release ammonia into the air. Ammonia can combine with other chemicals to form compounds that contribute to acid rain. 6. Biogeochemical Cycle Linked with Lightning (Nitrogen Cycle) Lightning plays a role in the nitrogen cycle by helping convert nitrogen gas (N₂) into a form that plants can use. Here’s how it works: Nitrogen in the Atmosphere: Most of the Earth’s atmosphere is made up of nitrogen gas (N₂), but plants can’t use this type of nitrogen directly. Lightning and Nitrogen Fixation: When lightning strikes, the heat from the lightning bolt breaks the strong bonds in nitrogen gas molecules, causing nitrogen atoms to combine with oxygen in the air to form nitrogen oxides (NOₓ). Formation of Nitrates: These nitrogen oxides mix with water in the atmosphere and form acids, which then fall as rain. This rain carries nitrates (NO₃⁻) into the soil, which plants can absorb and use for growth. Entry into the Ecosystem: Once the nitrates are in the soil, plants absorb them through their roots and use them to create proteins, which are then passed through the food chain to animals. This process helps maintain the flow of nitrogen through ecosystems. Lightning helps “fix” nitrogen in the atmosphere, making it available to plants, which is crucial for their growth and for the entire food web. These explanations break down complex processes into understandable steps, helping you connect how each part works within the bigger picture. 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