Chemistry and Biology Basics

Chemistry

• Particle Theory: All matter is composed of tiny, constantly moving particles. Particles attract each other and have spaces between them. Increased temperature means faster particle movement.
• Types of Matter:
  • Element: A pure substance, like hydrogen (H₂).
  • Compound: Two or more different atoms combined, like carbon dioxide (CO₂).
  • Solution: A uniform-looking mixture, like coffee.
  • Mechanical Mixture: Visible components, like pizza.
• Chemical vs. Physical Changes: Chemical changes involve color change, heat/light production, precipitate formation or gas release. Dissolving is generally a physical change.
• Density: Density equals mass divided by volume. Use the density triangle to rearrange formulas.
• Atomic Structure: Understanding atomic structure (like Bohr diagrams) is important.

Biology

• Habitat vs. Niche:
  • Habitat: The place where an organism lives.
  • Niche: An organism's role in its ecosystem (what it does).
• Carbon Cycle: Photosynthesis and cellular respiration are key processes.
• Food Webs: Understand trophic levels (producers, primary consumers, etc.).
• Bioaccumulation: Toxins accumulate through food chains, such as pesticides affecting hawks.

Physics

• Electric Charges: Opposite charges attract, and like charges repel.
• Current vs. Static Electricity: Understand their differences and definitions.
• Circuit Diagrams: Know the symbols and how to draw series and parallel circuits.
• Ohm's Law: Relates voltage, current, and resistance.

Astronomy

• Seasons: Earth's tilt causes variations in sunlight distribution throughout the year.
• Pluto's Classification: Understand criteria for classifying planets versus dwarf planets.
• Asterisms vs. Constellations: Asterisms are subsets of constellations, like the Big Dipper.