Unit 1: Chemistry Basics

Unit 1: Chemistry

• Balancing Chemical Equations: Ensure the same number of each type of atom is on both sides of the equation, following the Law of Conservation of Mass. Examples show how to balance equations.
• Evidence of Chemical Change: Look for signs like color change (e.g., rust), gas production (bubbles), precipitate formation (solid in a solution), temperature change, light emission, or odor change.
• Types of Reactions:
  • Synthesis: Two or more substances combine to form one. (e.g., 2H₂ + O₂ → 2H₂O)
  • Decomposition: One substance breaks down into simpler substances. (e.g., 2H₂O → 2H₂ + O₂)
  • Single Displacement: One element replaces another in a compound. (e.g., Zn + CuSO₄ → ZnSO₄ + Cu)
  • Double Displacement: Elements in two compounds swap places. (e.g., AgNO₃ + NaCl → AgCl + NaNO₃)
• Chemical Names and Formulas:
  • Ionic compounds: Formed from a metal and a nonmetal (e.g., NaCl).
  • Covalent compounds: Formed from two nonmetals (e.g., CO₂).
  • Polyatomic ions: Groups of atoms with a charge (e.g., SO₄²⁻, OH⁻).
• Ionic vs. Covalent Bonds:
  • Ionic Bonds: Electrons are transferred between a metal and a nonmetal.
  • Covalent Bonds: Electrons are shared between nonmetals.

Unit 2: Climate Change

• Effects of Climate Change:
  • Rising sea levels due to melting glaciers.
  • More frequent/extreme weather events (storms, droughts).
  • Loss of biodiversity as species struggle to adapt.
• Climate Initiatives:
  • Paris Agreement: Global effort to limit warming to 1.5°C.
  • Renewable energy (solar, wind) replacing fossil fuels.
  • Reforestation to absorb CO2.
• Water and Climate:
  • Water bodies moderate climate by absorbing/releasing heat.
  • Water vapor traps heat (greenhouse gas).
  • Ice reflects sunlight; less ice means more warming.
• Greenhouse Effect:
  • Natural: Keeps Earth warm enough for life by trapping heat.
  • Anthropogenic: Burning fossil fuels adds excess CO2, causing warming.
• 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

• Snell's Law: Describes how light bends when passing between materials with different densities (refraction). Formula: n₁sinθ₁ = n₂sinθ₂
• Heat Transfer:
  • Conduction: Heat transfer through solids.
  • Convection: Heat transfer in fluids.
  • Radiation: Heat transfer by electromagnetic waves.
• Electromagnetic Spectrum: Visible light (ROYGBIV), other forms like radio waves, gamma rays with varying wavelengths.
• Mirrors and Lenses (SALT): Describes characteristics like size, attitude, location, and type of image formed.
• 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

• Mitosis: Cell division resulting in two identical daughter cells. Key stages: Prophase, Metaphase, Anaphase, Telophase.
• Cell Cycle: Interphase (cell growth and DNA replication) and Mitosis (division).
• Systems Interaction: Respiration and circulation work together to provide necessary oxygen and energy to cells.
• Cancer: Uncontrolled cell division due to DNA damage forming tumors and potentially spreading.
• Cell Organelles:
  • Plant cells: Chloroplasts (photosynthesis), cell wall (structure).
  • Animal cells: Centrioles (mitosis), lysosomes (waste breakdown).