Comprehensive Study Notes: General Science and Engineering Foundations of Science and Engineering

Matter and Dalton's Atomic Theory

• Matter: Defined as anything that has mass and takes up space (volume). It is composed of tiny particles called atoms, a concept first proposed by Democritus.

• Examples of Matter: Air, water, people, and rocks are all classified as matter because they possess mass and occupy space.

• Dalton's Atomic Theory: Consists of four fundamental ideas:

  1. All matter is made of atoms.

  2. Atoms of the same element are identical.

  3. Atoms of different elements are different.

  4. During chemical reactions, atoms rearrange.

The Structure of an Atom and Atomic Notation

• Atom: The smallest unit of matter that cannot be divided by chemical means.

• Parts of an Atom:

  • Proton: Carries a positive charge ($+$, localized in the nucleus.

  • Neutron: Carries no charge ($0$), localized in the nucleus.

  • Electron: Carries a negative charge ($-$), localized in the space around the nucleus.

• Chemical Symbols: Defined by specific capitalization rules:

  • One-letter symbols must be a capital letter (e.g., $H$, $C$, $O$).

  • Two-letter symbols must have the first letter capitalized and the second letter lowercase (e.g., $Na$, $Fe$, $Ca$).

• Periodic Table Organization:

  • Elements are arranged by increasing atomic number.

  • Atomic Number: Represents the number of protons in the nucleus. In a neutral atom, the number of protons equals the number of electrons.

  • Atomic Mass: The sum of protons and neutrons ($\text{Protons} + \text{Neutrons}$).

• Calculating Neutrons: Use the formula: $\text{Neutrons} = \text{Atomic Mass} - \text{Atomic Number}$.

  • Example (Carbon): Atomic mass is approximately $12$ and atomic number is $6$. Therefore, $12 - 6 = 6$ neutrons.

• Distinguishing Matter Types:

  • Metals: Shiny, conduct heat and electricity, and are malleable (e.g., $Fe$).

  • Nonmetals: Dull and are poor conductors (e.g., $O$).

  • Metalloids: Possess properties of both metals and nonmetals (e.g., $Si$).

Molecules, Elements, and Compounds

• Molecules: Formed when two or more atoms are bonded together.

  • Examples: $H_2$, $O_2$, $H_2O$, $CO_2$.

  • Analogy: Atoms are like letters; molecules are like words.

• Elements: Contain only one type of atom and cannot be broken down chemically.

  • Examples: $O_2$ (still an element because it only has oxygen), $C$, $Fe$.

• Compounds: Contain different elements chemically bonded together.

  • Examples: $H_2O$, $CO_2$, $NaCl$.

  • Logic Rule: All compounds are molecules, but not all molecules are compounds (e.g., $O_3$ is a molecule because it has multiple atoms, but not a compound because it only has one type of element).

Counting Atoms in Formulas

• H2O: $H = 2$, $O = 1$. Total = $3$ atoms.

• CO2: $C = 1$, $O = 2$. Total = $3$ atoms.

• Ca3(PO4)2: Multiply elements inside the brackets by the subscript outside. $Ca = 3$, $P = 1 \times 2 = 2$, $O = 4 \times 2 = 8$. Total = $13$ atoms.

Properties of Matter and Density

• Mass: The amount of matter in an object, measured with a balance in grams ($g$).

• Volume: The amount of space occupied by an object. It can be measured using a ruler (regular solids), a graduated cylinder (liquids), or water displacement (irregular solids).

  • Equivalency: $1 \text{ mL} = 1 \text{ cm}^3$.

• Non-characteristic Properties: Characteristics that cannot identify a substance because they change based on quantity (e.g., mass, volume, shape, color, hardness, temperature, elasticity).

• Characteristic Properties: Unique characteristics that help identify a substance (e.g., density, melting point, boiling point). Water boils at $100^{\circ}C$ at normal pressure regardless of volume.

• Density ($\rho$): The amount of mass in a given volume.

  • Formula: $\rho = \frac{m}{V}$, where $m$ is mass and $V$ is volume.

  • Units: $g \text{ cm}^{-3}$ or $g \text{ mL}^{-1}$.

  • Density Triangle Conversions:

    • Determine Density: $\rho = \frac{m}{V}$

    • Determine Mass: $m = \rho \times V$

    • Determine Volume: $V = \frac{m}{\rho}$

  • Math Example (Density): If $m = 25.2 \text{ g}$ and $V = 18 \text{ mL}$, then $\rho = \frac{25.2}{18} = 1.4 \text{ g mL}^{-1}$.

  • Math Example (Mass): If $\rho = 19.3 \text{ g cm}^{-3}$ and $V = 500 \text{ cm}^3$, then $m = 19.3 \times 500 = 9650 \text{ g}$.

• Floating and Sinking: Water has a density of $1.0 \text{ g cm}^{-3}$. Substances with density less than $1$ float (e.g., Oil at $0.91 \text{ g cm}^{-3}$), while those with density greater than $1$ sink (e.g., Honey at $1.36 \text{ g cm}^{-3}$).

Transformations of Matter

• Physical Changes: Changes that do not alter the nature of the substance. No new substances are produced, molecules remain the same, and the change is usually reversible.

  • Examples: Melting, boiling, freezing, crushing, stretching, cutting, breaking glass, mixing substances without reaction.

  • Phase Changes:

    • Melting: Solid $\rightarrow$ Liquid

    • Solidification (Freezing): Liquid $\rightarrow$ Solid

    • Evaporation: Liquid $\rightarrow$ Gas

    • Condensation: Gas $\rightarrow$ Liquid

    • Sublimation: Solid $\rightarrow$ Gas

    • Deposition: Gas $\rightarrow$ Solid

• Chemical Changes: Changes that alter the nature of matter and produce new substances. Molecules rearrange, and the change is usually irreversible.

  • Indicators of Chemical Change:

    1. Color change

    2. Gas production (bubbles)

    3. Temperature change

    4. Light production

    5. Formation of a precipitate (solid formation)

• Types of Chemical Changes:

  • Combustion (Burning): Reaction with oxygen resulting in energy release. Produces $CO_2$, $H_2O$, and energy. (e.g., burning wood, candles, or gasoline).

  • Oxidation: Reaction with oxygen (e.g., rusting iron, apple turning brown).

  • Synthesis: Two or more substances combine to make a new substance ($A + B \rightarrow AB$). Example: Photosynthesis ($CO_2 + H_2O + \text{Sunlight} \rightarrow C_6H_{12}O_6 + O_2$).

  • Decomposition: One substance breaks down into simpler substances ($AB \rightarrow A + B$). Example: Cellular Respiration ($C_6H_{12}O_6 + 6O_2 \rightarrow 6CO_2 + 6H_2O + \text{Energy (ATP)}$).

• Conservation of Matter: The quantity of matter remains constant before and after a change. Antoine Lavoisier stated: "Nothing is lost, nothing is created, everything is transformed."

• Conservation of Atoms: The total number of atoms for each element must be equal on both the reactant and product sides of a reaction.

  • Example: $CH_4 + 2O_2 \rightarrow CO_2 + 2H_2O$. There is always $1$ Carbon, $4$ Hydrogen, and $4$ Oxygen atoms on both sides.

Biology: Living Things and the Cell

• Characteristics of Living Things:

  1. Made of cells.

  2. Respond to stimuli (light, heat, sound, hunger).

  3. Exchange substances with the environment (nutrition, respiration).

  4. Grow and develop.

  5. Need energy.

  6. Reproduce.

  7. Adapt to environment.

• Cell: The basic unit of all living things.

• Common Cell Organelles:

  • Cell Membrane: Controls what enters and leaves the cell ("Security Guard").

  • Cytoplasm: Jelly-like material holding organelles.

  • Nucleus: Controls activities and contains genes/hereditary information ("Brain").

  • Mitochondria: Produces energy via cellular respiration ("Powerhouse").

  • Ribosomes: Make proteins ("Factory").

  • Endoplasmic Reticulum (ER): Transports materials ("Highway").

  • Golgi Body: Packages and transports materials ("Post Office").

  • Vacuoles: Store food, water, and waste ("Storage Room").

• Plant-Specific Organelles:

  • Cell Wall: Provides support and rectangular shape ("Brick Wall").

  • Chloroplasts: Perform photosynthesis using chlorophyll, a green pigment ("Solar Panel").

  • Large Central Vacuole: Much larger than animal vacuoles.

Human Reproduction and Development

• Reproduction: Process by which organisms produce individuals of the same species.

• Male System:

  • Testicles: Produce sperm and male hormones (Spermatogenesis).

  • Semen: Mixture of sperm and fluids from seminal vesicles, prostate, and Cowper’s glands.

  • Path of Sperm: Testicles $\rightarrow$ Epididymis $\rightarrow$ Vas deferens $\rightarrow$ Urethra $\rightarrow$ Penis.

• Female System:

  • Ovaries: Produce eggs (Oogenesis) and female hormones.

  • Fallopian Tubes: Site where fertilization typically occurs.

  • Uterus: Location where the baby developments; lined by the endometrium.

• Fertilization: The union of a male gamete (sperm, $23$ chromosomes) and a female gamete (ovum, $23$ chromosomes) to form a zygote ($46$ chromosomes).

• Menstrual Cycle: Typically lasts $28$ days.

  • Days 1–5: Menstruation (shedding of the endometrium).

  • Day 14: Ovulation (release of an egg). This occurs exactly $14$ days before the next period.

• Fertile Window: Begins $4$ days before ovulation and ends $1$ day after (as sperm survives $3 \text{--} 5$ days and the ovum survives $24$ hours).

• Contraception:

  • Hormonal: Pill, patch, injection, implant, vaginal ring, IUD, emergency pill.

  • Non-Hormonal: Condom, female condom, spermicide, copper IUD, vasectomy, tubal ligation.

• STBBIs: Infections spread via sex or blood. Bacterial examples include Chlamydia (most common in North America), Gonorrhea (risk of infertility), and Syphilis. All three are treated with antibiotics.

Geology: Minerals, Rocks, and Soil

• Mineral: A naturally occurring, inorganic solid with a crystal structure and definite chemical composition.

• Identification Tests: Color, Streak (powder color), Luster (metallic, glassy, pearly, etc.), Magnetism, Acid Test (effervescence), and Cleavage (how it breaks).

• Mohs Hardness Scale: From $1$ (Softest: Talc) to $10$ (Hardest: Diamond).

  1. Talc, 2. Gypsum, 3. Calcite, 4. Fluorite, 5. Apatite, 6. Orthoclase, 7. Quartz, 8. Topaz, 9. Corundum, 10. Diamond.

• Rock Types:

  • Igneous: Cooling of magma (Intrusive: large crystals like Granite) or lava (Extrusive: small crystals like Obsidian).

  • Sedimentary: Formed in layers (strata); may contain fossils. Includes Clastic (Sandstone), Chemical (Rock salt), and Organic (Coal/Limestone).

  • Metamorphic: Rocks changed by heat/pressure. Examples include Slate, Quartzite, Gneiss, and Marble.

• Soil Horizons:

  • O-Horizon: Organic matter (humus).

  • A-Horizon: Topsoil (supports life).

  • B-Horizon: Subsoil (minerals).

  • C-Horizon: Fragmented parent rock.

  • R-Horizon: Bedrock.

• Soil Quality: Measured by minerals/nutrients, pH (typically $4 \text{--} 10$, preference for $5 \text{--} 7$), and permeability (clay is less permeable than sandy soil).

Meteorology and Energy

• Solar Energy: Drives the water cycle (evaporation $\rightarrow$ condensation $\rightarrow$ precipitation) and powers food chains via photosynthesis.

• Wind: Air movement from high pressure to low pressure areas caused by temperature differences.

• Clouds:

  • Cirrus: High, wispy.

  • Stratus: Low, drizzle.

  • Cumulus: Puffy, fair weather.

  • Cumulonimbus: Storm clouds (thunder/lightning/tornadoes).

• Storms: Tornadoes are funnel-shaped spinning columns; Hurricanes/Cyclones are storms with winds exceeding $119 \text{ km/h}$ formed over warm oceans.

• Energy Sources:

  • Renewable: Hydroelectric, wind, solar, geothermal, biomass.

  • Non-Renewable: Fossil fuels (coal, oil, natural gas — contribute to greenhouse gases/acid rain) and Nuclear (uranium fission — efficient but produces radioactive waste).

Astronomy and Gravitation

• Gravity: Force of attraction between objects with mass.

  • Mass $\uparrow \rightarrow$ Gravity $\uparrow$ (Direct relationship).

  • Distance $\uparrow \rightarrow$ Gravity $\downarrow$ (Indirect relationship).

• Mass vs. Weight: Mass is the constant amount of matter. Weight is the force of gravity and changes depending on the gravitational field (e.g., lower on the Moon).

• Heliocentrism: The Sun is at the center of the solar system, containing about $98\%$ of its mass. This superseded Geocentrism (Earth-centered).

• Planetary Bodies:

  • Terrestrial (Rocky): Mercury, Venus, Earth, Mars.

  • Gas Giants (Jovian): Jupiter, Saturn, Uranus, Neptune.

  • Asteroids: Rocky bodies mostly found in the belt between Mars and Jupiter.

  • Space Rocks: Meteoroid (in space) $\rightarrow$ Meteor (atmosphere/burning) $\rightarrow$ Meteorite (impacts ground).

• Magnetosphere: Earth's magnetic shield (created by iron/nickel core) that protects against Solar Wind. Auroras (Borealis/Northern, Australis/Southern) form in the thermosphere when solar wind particles collide with atmospheric particles.

Engineering and Motion

• Technological System: A group of parts working together. Characteristics include Function, Controls (Mechanical, Electrical, Optical), Inputs, Processes, and Outputs (Desired vs. Undesired Waste).

• Energy Types:

  • Kinetic: Energy of motion.

  • Potential: Stored energy. Types include Gravitational (height), Elastic (stretch), and Chemical (batteries/food).

  • Thermal: Heat energy; generated by friction or combustion.

• Law of Conservation of Energy: Energy cannot be created or destroyed; it only transforms (e.g., Lightbulb: Electrical $\rightarrow$ Luminous + Thermal).

• Simple Machines:

  1. Inclined Plane: Angle that reduces force over distance.

  2. Wedge: Two inclined planes used to split.

  3. Screw: Wrapped inclined plane; converts rotation to translation.

  4. Lever: Consists of Effort, Fulcrum, and Load (Resistance).

     • 1st Class: Fulcrum in middle (Seesaw).

     • 2nd Class: Load in middle (Wheelbarrow).

     • 3rd Class: Effort in middle (Tweezers).

  5. Wheel and Axle: Reduces force needed for motion.

  6. Pulley: Changes direction of force.

• Mechanical Systems:

  • Transmission: Transfers the SAME motion (e.g., Gear train, belt/pulley, chain/sprocket).

  • Transformation: Changes the motion TYPE (e.g., Rack and Pinion: Rotational $\rightarrow$ Translational; Cam and Follower: Rotational $\rightarrow$ Bidirectional Translational).

Taxonomy and Adaptation

• Species: Organisms with similar DNA and physical traits that can produce fertile offspring.

• Classification Order: Domain $\rightarrow$ Kingdom $\rightarrow$ Phylum $\rightarrow$ Class $\rightarrow$ Order $\rightarrow$ Family $\rightarrow$ Genus $\rightarrow$ Species.

• Binomial Nomenclature: Genus (Capitalized) + Species (Lowercase). (e.g., Panthera tigris).

• Adaptations:

  • Physical: Characteristics like bird beaks, camouflage (blending), or mimicry (imitating another species).

  • Behavioral: Actions like migration, hibernation, or phototropism (plants growing toward light).