Introduction to Chemistry Flashcards

Course Introduction and Course Logistics

Class Context: The course is taking place in Spring 2026, 2011.
Review Ratio: Approximately $40\%$ of the class material is a review of Chemistry 101, though it will be explored in greater depth.
Lecture Structure: * The material is split into Lecture 1 (today) and Lecture 2, correlating directly with sections in the textbook. * Section 1.1 covers "What is Chemistry?" * Breaks: The instructor initially planned for automatic breaks but decided against them for the first day to gauge the pace. Future lectures may include a 5- to 10-minute break.

The Broad Definition and Scope of Chemistry

General Definition: Chemistry is the study of the composition, properties, and interaction of matter. It is omnipresent and frequently referred to as the "Central Science."
Everyday Examples: * Food and Drink: Found in coffee, the fuel for cars, cooking (chemical reactions), fermentation (kombucha, beer), and digestion. * Health and Hygiene: Chemistry is responsible for soaps, medicines, and vaccines (e.g., the Hantavirus vaccine, noted as being patented by the US Army). * Technology: Found in electronics, fuels, and polymers.
Pop Culture Reference: The anime Doctor Stone is highlighted for its sound scientific principles, including an episode where the protagonist makes homemade soap.
Interdisciplinary Rivalry: The instructor notes a playful disagreement with their physicist grandfather regarding which science is most fundamental, arguing that physics cannot exist without atoms (chemistry).

Historical Development of Chemical Theory

Stone Age: Cavemen created tools and carved wood. They could change the shape of objects but lacked the frontal lobe development to change the chemical composition of matter.
Early Civilizations: Developed pottery, extracted metals, created alloys like bronze, and produced alcohol.
600 BCE (Greek Philosophers): Proposed that matter is composed of four elements: earth, air, fire, and water. This period is referred to as the Hellenistic period of "Divine Art." * Aristotle: Considered both a philosopher and a chemist. He observed that chewing willow bark (a natural source of aspirin) could ease pain. * Empedocles: Formally introduced the four elements. * Democritus: Proposed that all matter is made up of eternal, indivisible, indestructible, and infinitely small substances called atoms. * The word "atom" comes from the Greek term for "indivisible." * He theorized that solids were made of small pointy atoms, while liquids were made of large round atoms. * He believed the universe consisted only of atoms and empty space; his views on the origin of the universe parallel the Big Bang theory.
Alchemy: Known for attempts to transform base metals into gold. Alchemists isolated drugs and dyes and spread extensive chemical knowledge. Historically, female alchemists were sometimes stigmatized or accused of witchcraft.
Modern Era: Characterized by the development of the scientific method, drug synthesis, and atomic theory. Advancements in chemistry have increased the average human lifespan from approximately 40 years to over 100.

The Central Science: Conceptual Interconnectivity

Interdisciplinary Ties: Chemistry connects various major fields, including: * Biology: Biochemistry and molecular biology. * Geology: Understanding the atomic makeup of rocks and minerals. * Medicine: Drug production and pharmaceutical research. * Astronomy: Analyzing the chemical composition of gases and compounds on other planets via NASA data. * Physics: Studying the behavior of atoms.

Modern Applications and Biochemical Innovations

Biochemistry Focus: The instructor's specialty is biochemistry and molecular biology.
Progesterone Case Study: A critical hormone for women's health. * Comparing hormonal cycles: Men typically cycle testosterone within a single day. Women have a complex 30-day cycle involving estrogen and progesterone. * Historical Source: Originally derived from scarce animal sources.
Cortisone Case Study: Used as a sterile treatment (cortisol) for arthritis. * Synthesis Challenge: Originally required a 36-step chemical synthesis, making mass production difficult.
Percy Julian’s Innovation: A scientist who discovered that soybeans (specifically soybean sterols) could be used to efficiently synthesize progesterone, testosterone, and cortisone. * Impact: This made these drugs widely available, affordable, and saved lives through cheap production costs.

The Scientific Method and Evidence-Based Reasoning

Hypothesis: A tentative explanation used to guide data collection that can be tested and refined.
Experimentation: Testing the hypothesis (e.g., throwing an egg on the ground to see if it breaks).
Scientific Law vs. Scientific Theory: * Law: A statement of fact deduced from observation, often summarized by a mathematical equation (e.g., the Law of Gravity). It summarizes a vast number of observations and describes/predicts natural phenomena. Laws cannot be easily disproven. * Theory: A well-sustained, comprehensive, and testable explanation for a class of phenomena. Theories can be disproven by a single experiment and require broad agreement over time.
Observation vs. Inference: * Observation: Active acquisition of info using the five senses or instruments (e.g., measuring wind speed during a tornado). * Inference: A conclusion or opinion formed based on known facts or past evidence (e.g., predicting future behavior based on psychology).

The Three Domains of Chemistry

Macroscopic Domain: Things large enough to be seen or touched (e.g., a desk, color, density, boiling point, solubility).
Microscopic Domain: Entities mostly invisible to the naked eye, such as atoms, molecules, ions, and electrons. This domain is often visualized in the mind (e.g., imagining the $H_2O$ lattice structure in ice).
Symbolic Domain: The specialized language of chemistry, including chemical symbols, formulas, and equations (e.g., writing the decomposition of water as $2H_2O \rightarrow 2H_2 + O_2$ ).

Detailed Classification of Matter

Pure Substances: Cannot be separated by physical processes. * Elements: Pure substances that cannot be broken down chemically (e.g., everything on the Periodic Table like Iron, Gold, Oxygen). * Compounds: Consist of two or more elements in fixed ratios; they can be broken down into simpler substances via chemical reactions (e.g., Water, Sucrose ( $C_{12}H_{22}O_{11}$ ), Sodium Chloride ( $NaCl$ )).
Mixtures: Can be separated by physical processes. * Heterogeneous: vVaries in composition; not uniform (e.g., Italian dressing, chocolate chip cookies, granite). * Homogeneous: Consists of a uniform composition throughout; also called a solution (e.g., Gatorade, air, maple syrup, gasoline, saltwater).

States of Matter

Solids: Have a definite shape and volume. Particles are packed closely with strong interactions and are non-compressible.
Liquids: Have a definite volume but assume the shape of the container. Particles move freely below the surface (surface tension) and are nearly non-compressible.
Gases: Assume both the shape and volume of the container. Particles move randomly and are highly compressible.
Plasma: A fourth state of matter. It is a high-temperature gaseous state containing electrically charged particles (ions and electrons). * Found in: Sun and stars (stellar interiors), Plasma TVs (using UV light to excite phosphors), lightning strikes, and specialized lab instruments used to detect trace metals.

Physical and Chemical Properties and Changes

Physical Property: Observed without changing composition (e.g., density, color, hardness, melting point, boiling point, electrical conductivity).
Physical Change: Change in state or form without changing chemical identity (e.g., melting glass, dissolving sugar in water, grinding a solid into powder).
Chemical Property: The ability to change into a different kind of matter (e.g., flammability, toxicity, acidity, reactivity with water, tendency to rust).
Chemical Change: Produces matter that differs from the original (e.g., iron rusting, cooking an egg, a banana turning brown due to oxidation, a battery discharging/corroding).

Extensive and Intensive Properties

Extensive Properties: Depend on the amount of matter present. The value scales with quantity (e.g., mass, volume, length, total heat energy).
Intensive Properties: Do not depend on the amount of matter present. The value remains the same regardless of sample size (e.g., temperature, density, color, boiling point, melting point).

Quantitative Fundamentals: Measurements and Units

Three Essential Components of Measurement: 1. Number: Magnitude or size (decimal, scientific notation, etc.). 2. Unit: A standard for comparison (Grams, Meters, Seconds). The instructor emphasizes that units are vital (e.g., $100\,mg$ vs. $100\,g$ of phenobarbital is a lethal difference). 3. Uncertainty: Limits of the measurement tool.
Standard SI Units: * Length: meter ( $m$ ) * Mass: kilogram ( $kg$ ) * Time: second ( $s$ ) * Temperature: Kelvin ( $K$ ) * Amount: mole ( $mol$ ) * Electric Current: ampere ( $A$ ) * Luminous Intensity: candela ( $cd$ )
Metric Prefixes to Memorize (Nano to Giga): * Giga ( $G$ ): $10^9$ * Mega ( $M$ ): $10^6$ * Kilo ( $k$ ): $10^3$ * Hecto ( $h$ ): $10^2$ * Deca ( $da$ ): $10^1$ * Base Unit: $10^0$ * Deci ( $d$ ): $10^{-1}$ * Centi ( $c$ ): $10^{-2}$ * Milli ( $m$ ): $10^{-3}$ * Micro ( $\mu$ ): $10^{-6}$ * Nano ( $n$ ): $10^{-9}$ * Pico ( $p$ ): $10^{-12}$ * Extreme prefixes (Quetta $10^{30}$ and Quenna $10^{-30}$ ) are mentioned but not required for exams.

Atomic Scale and Mass

Atom Size Metaphor: * A single spider web strand has a diameter of roughly $0.0001\,cm$ . * A carbon atom is approximately $1.5 \times 10^{-8}\,cm$ . * It takes about 7,000 carbon atoms to span the width of one spider web strand. * A billion lead atoms weigh only $3 \times 10^{-13}\,g$ .
Molecules: Two or more atoms joined by chemical bonds. Examples include diatomic molecules like hydrogen ( $H_2$ ), oxygen ( $O_2$ ), and nitrogen ( $N_2$ ), as well as complex molecules like phosphorus ( $P_4$ ) and glucose ( $C_6H_{12}O_6$ ).

Conversion and Dimensional Analysis

Law of Conservation of Matter: No detectable change in the total quantity of matter during chemical or physical changes. * Example 1: Brewing beer. Glucose converts to ethanol and $CO_2$ . The mass remains the same. * Example 2: Car battery. Lead ( $Pb$ ), lead oxide ( $PbO_2$ ), and sulfuric acid ( $H_2SO_4$ ) convert to lead sulfate ( $PbSO_4$ ) and water. Mass is conserved.
Conversion Examples: * Converting meters to centimeters: $15\,m \times \frac{100\,cm}{1\,m} = 1500\,cm$ . * Converting decigrams to hectograms: Requires a conversion factor of $10,000$ . * Converting milliliters to deciliters: $3.5\,mL \times \frac{0.01\,dL}{1\,mL} = 0.035\,dL$ . * Converting joules to kilojoules: $17\,J \times \frac{1\,kJ}{1000\,J} = 0.017\,kJ$ .

Questions & Discussion

Student Observation: A student pointed out a mistake on a diagram regarding the classification of mixtures where the "yes" and "no" labels for uniform composition were swapped. The instructor acknowledged the error, noting the slides were a combination of their own and Dr. Schwab's.
Velocity of Light: A student questioned a data point about the distance light travels. The instructor clarified that the point was to illustrate that light travels extremely quickly, even if a unit was slightly misstated in the example (should be meters per second).
Dimensional Analysis Preference: A student asked about using decimals versus whole numbers in conversion factors. The instructor suggested using the "Unit Timeline" and moving decimals as a fail-safe method, especially if dimensional analysis is confusing.
Class Participation: The instructor considered having students do problems on the board but decided against it to respect different learning preferences.