Science Study Guide PDF
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This document is a study guide covering various science concepts, from chemistry and climate change to physics and biology. It includes explanations and examples for a secondary school level. The guide outlines key topics and concepts in each field.
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Unit 1: Chemistry 1. Balancing Chemical Equations: ○ To balance equations, ensure the same number of atoms of each element is on both sides of the equation, following the Law of Conservation of Mass. Example: Propane combustion: ○ C3H8+5O2→3CO2+4...
Unit 1: Chemistry 1. Balancing Chemical Equations: ○ To balance equations, ensure the same number of atoms of each element is on both sides of the equation, following the Law of Conservation of Mass. Example: Propane combustion: ○ C3H8+5O2→3CO2+4H2O Here, 3 carbons, 8 hydrogens, and 10 oxygens are balanced. 2. Evidence of Chemical Change: ○ Look for signs like: Color change (e.g., rust forming on iron). Gas production (bubbles from baking soda + vinegar). Precipitate (solid forming in a solution, like BaSO4BaSO4in water). Temperature change (heat released in combustion). Light or odor change (e.g., fireworks). 3. Types of Reactions: ○ Synthesis: Two or more substances combine to form one (e.g., 2H2+O2→2H2O2H2+O2→2H2O). ○ Decomposition: One substance breaks into simpler ones (e.g., 2H2O→2H2+O22H2O→2H2+O2). ○ Single Displacement: One element replaces another (e.g., Zn+CuSO4→ZnSO4+CuZn+CuSO4→ZnSO4+Cu). ○ Double Displacement: Exchange of ions (e.g., AgNO3+NaCl→AgCl+NaNO3AgNO3+NaCl→AgCl+NaNO3). 4. Chemical Names and Formulas: ○ Ionic compounds: Metal + non-metal (e.g., NaClNaCl). ○ Covalent compounds: Non-metals share electrons (e.g., CO2CO2). ○ Polyatomic ions: Groups of atoms with a charge (e.g., SO42−SO42−, OH−OH−). 5. Ionic vs. Covalent Bonds: ○ Ionic bonds: Electrons are transferred; form between metals and non-metals (e.g., NaClNaCl). ○ Covalent bonds: Electrons are shared; form between non-metals (e.g., H2OH2O). Unit 2: Climate Change 1. Effects of Climate Change: ○ Rising sea levels due to melting glaciers. ○ More frequent/extreme weather (storms, droughts). ○ Loss of biodiversity as species struggle to adapt. 2. Climate Initiatives: ○ Paris Agreement: Global effort to limit warming to 1.5°C. ○ Renewable energy (solar, wind) replacing fossil fuels. ○ Reforestation to absorb CO2 3. Water and Climate: ○ Water bodies moderate climate by absorbing/releasing heat. ○ Water vapor traps heat (greenhouse gas). ○ Ice/albedo effect: Ice reflects sunlight; less ice means more warming. 4. Greenhouse Effect: ○ Natural: Keeps Earth warm enough for life by trapping some heat. ○ Anthropogenic: Burning fossil fuels adds excess CO2CO2, causing warming. 5. Indicators of Climate Change: ○ Melting glaciers and ice caps. ○ Rising sea levels from thermal expansion. ○ Shifts in wind/ocean patterns affecting weather. Unit 3: Physics 1. Snell’s Law: ○ Describes refraction: Light bends when passing between materials with different densities. Formula: n1sinθ1=n2sinθ2n1sinθ1=n2sinθ2 Example: Light slows and bends toward the normal when entering water. 2. Heat Transfer: ○ Conduction: Heat moves through solids (e.g., touching a hot pan). ○ Convection: Heat moves in fluids (e.g., warm air rising). ○ Radiation: Heat travels as electromagnetic waves (e.g., sunlight). 3. Electromagnetic Spectrum: ○ Visible: ROYGBIV (Red = longest wavelength, Violet = shortest). ○ Invisible: Radio (longest wavelength), X-rays, gamma rays (shortest). 4. Mirrors and Lenses (SALT): ○ SALT: Size, Attitude, Location, Type. ○ Example: Convex mirrors create smaller, upright, virtual images. 5. Light Emissions: ○ Chemiluminescence: Light from a chemical reaction. ○ Bioluminescence: Light from living organisms (e.g., fireflies). ○ LEDs: Efficient, low-energy artificial light. Unit 4: Biology 1. Mitosis: ○ Stages: Prophase: Chromosomes condense. Metaphase: Chromosomes align in the middle. Anaphase: Chromatids separate. Telophase: Two nuclei form. ○ Importance: For growth and tissue repair. 2. Cell Cycle: ○ Interphase: Cell grows, DNA replicates. ○ Mitosis: Division into two identical daughter cells. 3. Systems Interaction: ○ Respiratory system takes in oxygen. ○ Circulatory system transports oxygen to cells. ○ Necessary for energy production in cells. 4. Cancer: ○ Caused by uncontrolled cell division due to DNA damage. ○ Can form tumors and spread (metastasis). 5. Cell Organelles: ○ Plant cells: Chloroplasts (photosynthesis), cell wall (structure). ○ Animal cells: Centrioles (mitosis), lysosomes (waste breakdown).
