BSC 1010 Quiz Study Guide PDF

### Study Guide for BSC 1010 Quiz (Covering "What is Science?" and "The Chemical Context of Life") --- ### **Part 1: What is Science?** #### **1. Definition of Science** - **Science** is an **ever-changing body of knowledge** and a **systematic process** used to answer questions about the **natur...

### Study Guide for BSC 1010 Quiz (Covering "What is Science?" and "The Chemical Context of Life") --- ### **Part 1: What is Science?** #### **1. Definition of Science** - **Science** is an **ever-changing body of knowledge** and a **systematic process** used to answer questions about the **natural world**. - Science is not just for scientists; it’s for everyone. Everyone should be **scientifically literate**. - **Science is power!** – Neil deGrasse Tyson #### **2. Types of Science** - **Basic Science**: Driven by curiosity to advance knowledge (e.g., Ben Franklin flying a kite to learn about electricity). - **Applied Science**: Uses basic science to solve specific problems (e.g., Ben Franklin inventing the lightning rod). #### **3. Scientific Theory vs. Hypothesis** - **Scientific Theory**: A broad explanation based on many well-supported hypotheses (e.g., theory of gravity). - **Hypothesis**: A proposed explanation for one or more observations. It must be **testable** and **falsifiable** (can be proven false). - **Example**: "Drinking 10–12 cups of coffee daily for 30 days improves memory." #### **4. Characteristics of a Hypothesis** - Must be a **statement** (not a question). - Must be **specific** and **testable**. - Must be **falsifiable** (can be proven false). #### **5. Scientific Method** - **Steps**: 1. **Observation**: Notice something in the natural world. 2. **Question**: Formulate a question based on the observation. 3. **Hypothesis**: Propose a testable explanation. 4. **Experiment**: Design and experiment to test the hypothesis. 5. **Results**: Analyze the data and draw conclusions. 6. **Conclusion**: Support or reject the hypothesis. - **Controlled Experiment**: The best way to test a hypothesis. It involves: - **Independent Variable**: What do you change (e.g., giving MSX)? - **Dependent Variable**: What you measure (e.g., memory test scores). - **Control Group**: Does not receive the treatment (e.g., placebo). - **Random Assignment**: Minimizes bias by randomly assigning subjects to groups. - **Blind/Double-Blind Experiments**: Minimize bias by keeping participants and/or researchers unaware of who is receiving the treatment. #### **6. Bias in Science** - **Bias**: Any deviation from a "true" finding due to preconceived notions. - **Minimizing Bias**: - **Random Assignment**: Assign subjects randomly to groups. - **Placebo**: A substance with no therapeutic effect given to the control group. - **Single-Blind/Double-Blind Experiments**: Participants and/or researchers don’t know who receives the treatment. #### **7. Correlation vs. Causation** - **Correlation**: A relationship between two variables that is not expected by chance. - **Correlation does not imply causation**! Just because two variables are related doesn’t mean one causes the other. --- ### **Part 2: The Chemical Context of Life** #### **1. Matter, Atoms, and Elements** - **Matter**: Anything that has mass and takes up space. All matter is made of **atoms**. - **Element**: A substance consisting of only one kind of atom (e.g., hydrogen, carbon, oxygen). - **Atom Structure**: - **Protons**: Positively charged, located in the nucleus. - **Neutrons**: Neutral, located in the nucleus. - **Electrons**: Negatively charged, orbit the nucleus in electron shells. - **Atomic Number**: The number of protons in an atom (defines the element). - **Isotopes**: Atoms of the same element with different numbers of neutrons (e.g., Carbon-12 vs. Carbon-14). #### **2. Chemical Bonds** - **Covalent Bonds**: Atoms share electrons (strong bond). - **Polar Covalent Bond**: Electrons are shared unequally (e.g., water). - **Nonpolar Covalent Bond**: Electrons are shared equally. - **Ionic Bonds**: One atom takes an electron from another, creating ions (charged atoms). - **Cations**: Positively charged ions. - **Anions**: Negatively charged ions. - **Hydrogen Bonds**: Weak bonds between a hydrogen atom and an electronegative atom (e.g., N, O, F). - **Van der Waals Interactions**: Very weak attractions between oppositely charged atoms. #### **3. Water and Its Properties** - **Polarity**: Water is a polar molecule due to the unequal sharing of electrons between oxygen and hydrogen. - **Hydrogen Bonding**: Water molecules form hydrogen bonds, giving water unique properties: - **Cohesion**: Water molecules stick together (e.g., surface tension). - **Adhesion**: Water molecules stick to other substances (e.g., water climbing up a plant stem).  - **High Specific Heat**: Water resists temperature changes, making it a suitable habitat for life. - **High Heat of Vaporization**: It takes a lot of energy to turn water into vapor (e.g., sweating cools the body). - **Universal Solvent**: Water dissolves many substances due to its polarity. #### **4. Acids, Bases, and pH** - **Acids**: Release H⁺ ions in water, lowering pH (more acidic). - **Bases**: Release OH⁻ ions in water, raising pH (more basic). - **pH Scale**: Measures the concentration of H⁺ ions in a solution. - **pH 7**: Neutral (pure water). - **pH < 7**: Acidic. - **pH > 7**: Basic. - **Buffers**: Help maintain stable pH levels in living organisms (e.g., blood pH is maintained between 7.35 and 7.45). #### **5. Chemical Reactions** - **Reactants → Products**: Chemical reactions involve breaking and forming bonds. - **Activation Energy**: The energy needed to start a reaction. - **Hydrolysis**: Adding water breaks down complex molecules into simpler ones. - **Condensation**: Combines simpler molecules into complex ones, releasing water. --- ### **Key Concepts to Remember** - **Science is iterative and non-linear**: It involves repeated testing and revising hypotheses. - **Controlled experiments** are the gold standard for testing hypotheses. - **Water’s unique properties** (cohesion, adhesion, high specific heat) are critical for life. - **Chemical bonds** (covalent, ionic, hydrogen) determine how molecules interact. - **pH and buffers** are essential for maintaining homeostasis in living organisms. --- ### **Practice Questions** 1. **What is the difference between a hypothesis and a scientific theory?** 2. **Explain the steps of the scientific method using an example.** 3. **What is the difference between a polar and nonpolar covalent bond?** 4. **Why is water considered the "universal solvent"?** 5. **How do buffers help maintain pH balance in living organisms?** --- Good luck with your quiz! Review the key concepts and practice applying them to different scenarios.