Science PDF - Ideas Change, Cosmology, and More

Ideas Change - Cosmology Main Components of the Universe: Planets, stars, nebulae, galaxies, neutron stars, and black holes. Stability of Stars: Stars remain stable because the outward force of fusion balances the inward force of gravity. Nuclear Fusion:...

Ideas Change - Cosmology Main Components of the Universe: Planets, stars, nebulae, galaxies, neutron stars, and black holes. Stability of Stars: Stars remain stable because the outward force of fusion balances the inward force of gravity. Nuclear Fusion: Fusion is the process that generates heat and light in the sun’s core. Diagram: Show the fusion process, with hydrogen atoms combining to form helium and releasing energy. Sun as Closest Star. Star Characteristics: Stars differ in size, surface temperature, and color. Temperature-Color Relationship: Blue stars are hotter; red stars are cooler. Hertzsprung-Russell Diagram: Shows a star’s life cycle based on its temperature and luminosity. Star Life Cycle Terms: Main Sequence: Normal phase where stars fuse hydrogen. Red Giant: Expanded phase after hydrogen is used up. Supergiant: Large, bright stars in later stages. White Dwarf: Small, dense remnants after a star sheds outer layers. Heliocentric vs Geocentric Models: Geocentric: Earth-centered (outdated). Heliocentric: Sun-centered (current). Big Bang Theory: Universe began 13.8 billion years ago from a hot, dense point and expanded. Parallax: The method of measuring star distances using angles (d=1/p). Doppler Effect: Change in wave frequency as the source moves; applies to light and sound. Red and Blue Shifts: Redshift shows objects moving away; blueshift shows objects approaching. Cosmological Redshift: Hubble’s observation that galaxies are moving away, supporting an expanding universe. Fr. Georges Lemaître: Proposed the primeval atom concept, leading to the Big Bang Theory. Science of the Road Distance-Time Graphs: Plot distance over time to show speed. Speed Unit Conversion: Convert km/h to m/s and vice versa. Formula: Speed (m/s) = Speed (km/h) ÷ 3.6. Speed Types: Instantaneous Speed: Speed at any given moment.  Average Speed: Total distance divided by total time. Speed Equation: Speed = distance over time Acceleration: Rate of change of velocity. Units: m/s². Positive and Negative Acceleration: Speeding up vs. slowing down. Newton’s Laws: 1. Inertia: Objects stay at rest or in motion unless acted on. 2. Force, Mass, Acceleration: F = ma. 3. Action-Reaction: Every action has an equal and opposite reaction. Car Safety: Modern safety features (seatbelts, airbags) relate to Newton’s laws. Traffic Accident Analysis: Forces like acceleration and reaction time contribute to accidents. Genetics Reproductive Systems: Diagrams of male and female systems; key structures and functions. DNA, Genes, Chromosomes: DNA: Double helix structure discovered by Watson and Crick. Genes: Sections of DNA coding for traits. Chromosomes: DNA packed into structures in cells. DNA Replication: DNA makes an exact copy during cell division (mitosis and meiosis). Punnett Squares: Show genetic crosses and predict traits. Mutations: Changes in DNA base sequence; can be positive or negative. Mutagens: Environmental factors causing mutations. Biotechnology: Using organisms to develop products (e.g., GMOs, medicine). A Chemical World Part 2 Atom Structure: Protons (+), neutrons (neutral), electrons (-). Chemical Reactions: Indicators of chemical changes, such as color change, gas production, etc. Ions: Cations: Positively charged ions (lost electrons). Anions: Negatively charged ions (gained electrons). Bonding:  Ionic: Transfer of electrons. Covalent: Sharing of electrons. Types of Reactions: Composition: Combining substances. Decomposition: Breaking down compounds. Single/Double Displacement: Exchange of elements. Law of Conservation of Mass: Matter is neither created nor destroyed in chemical reactions. Combustion: Burning of a substance; complete (clean burn) vs. incomplete combustion (produces soot). Exothermic vs. Endothermic: Exothermic: Releases heat. Endothermic: Absorbs heat. Reaction Rate: Affected by temperature, concentration, surface area, and catalysts.