Test_1_Review_for_ISAT112

Steps in the Scientific Method

• 1. Observation: Noticing something interesting or unusual.

• 2. Question: Asking a question about the observation.

• 3. Hypothesis: Proposing an explanation or prediction based on the observation.

• 4. Experiment: Designing and conducting a test to explore the hypothesis.

• 5. Data Collection: Gathering measurements or observations during the experiment.

• 6. Analysis: Interpreting the data to see if it supports or contradicts the hypothesis.

• 7. Conclusion: Drawing conclusions based on the data analysis. If the hypothesis is supported, it may undergo further testing; if not, revision is needed.

• 8. Communication: Sharing results with the scientific community.

Null and Alternate Hypotheses

• Null Hypothesis (H₀): A statement asserting no effect or relationship between variables.

• Alternate Hypothesis (H₁): A statement suggesting there is an effect or relationship between variables, opposing the null hypothesis.

Variables in Experiments

Independent Variable

• The variable that is manipulated or changed in an experiment to observe its effect.

Dependent Variable

• The measured or observed variable in response to changes in the independent variable.

Controlled Variables

• Variables that are kept constant to ensure that results are solely due to manipulation of the independent variable.

Types of Errors

Random Errors

• Unpredictable errors arising from minor, uncontrollable variations (e.g., temperature fluctuations).

Systematic Errors

• Consistent errors from faulty measurement systems or biases leading to inaccurate results.

Human Errors

• Mistakes made by the experimenter (incorrect measurements, miscalculations).

Difference Between "Cradle to Grave" and "Cradle to Cradle"

Cradle to Grave

• Model considering the entire lifecycle of a product from creation to disposal, focusing on its impact and waste generation.

Cradle to Cradle

• Sustainable approach where products are designed for reuse, remanufacturing, or recycling, reducing landfill waste.

Green Chemistry

• Design of chemical products/processes minimizing hazardous substances use and generation, aiming to lessen environmental impact through sustainable practices.

Source and Sink

Source

• A location or process emitting substances (e.g., pollutants) into the environment.

Sink

• A location or process absorbing or storing substances (e.g., forests absorbing carbon dioxide).

Emergent Property

• A characteristic arising from interactions of simpler elements in a system, unpredictable from the individual parts (e.g., traffic jams).

Shifting Baselines

• Phenomenon where each generation perceives environmental conditions as normal based on personal experiences, often failing to recognize degradation from past states.

Three Pillars of Sustainability / "Triple Bottom Line"

Environmental Sustainability

• Focused on maintaining planetary health by reducing pollution and conserving resources.

Economic Sustainability

• Ensuring long-term economic activities offer stability and growth without resource depletion.

Social Sustainability

• Maintaining and improving equality and quality of life for all.

Sustainability

• Practice of meeting present needs without compromising future generations’ abilities to meet their own needs, balancing economic growth, social inclusion, and environmental protection.

Mixtures

• A combination of two or more substances that are physically combined, retaining individual properties separable by physical means. Examples: Air, salad.

Homogeneous Mixtures

• Uniform composition (e.g., saltwater).

Heterogeneous Mixtures

• Distinct phases/components (e.g., salad).

Elements

• Pure substances consisting of one type of atom, unbreakable by chemical means (e.g., gold, oxygen).

Compounds

• Substances formed by chemical bonds between different elements, possessing unique properties from elemental components (e.g., water, sodium chloride).

Atoms vs. Molecules

Atoms

• Smallest unit of an element, consisting of protons, neutrons, and electrons.

Molecules

• Formed by two or more chemically bonded atoms, retaining compound properties (e.g., H₂O, O₂).

Summary of Key Differences

• Mixtures: Physical combinations, components retain properties.

• Elements: Substances of one type of atom.

• Compounds: Chemically bonded substances.

• Atoms: Smallest unit of an element.

• Molecules: Group of bonded atoms, smallest unit of a compound.

Air Composition

• Nitrogen (N₂): 78%

• Oxygen (O₂): 21%

• Argon (Ar): 0.9%

• Carbon Dioxide (CO₂): 0.04% (varies with pollution)

• Human health impacted by gas balance necessary for respiration.

Regions of the Atmosphere

Troposphere

• Lowest layer with weather; extends 8-15 km.

Stratosphere

• Contains ozone layer, extends 15-50 km.

Mesosphere

• Where meteoroids burn up; extends 50-85 km.

Thermosphere

• High temperatures due to solar absorption; extends 85-600 km.

Exosphere

• Outermost layer; transitions to space; starts at 600 km.

Oxygen's Role in Combustion

• Essential for combusting fuel, producing CO₂ and H₂O while releasing energy.

Ideal Gas Law Components

• Equation: PV = nRT

  • P: Pressure

  • V: Volume

  • n: Moles

  • R: Ideal gas constant (8.31 J/mol·K)

  • T: Temperature in Kelvin

• Demonstrates relationship between pressure, volume, and temperature of gas.

Pollutant Movement

Diffusion

• Movement from high to low concentration.

Convection

• Heat/pollutants move with air/liquids.

Settling

• Heavier pollutants settle due to gravity.

Air Pollution in Urban Areas

• High population leads to increased emissions, traffic congestion, and pollutant trapping by buildings.

Health Risk Assessment

1. Hazard: Inherent dangerous property of a substance (e.g., chemicals).

2. Exposure: Level/frequency of contact with a hazard.

• Health risk determined by hazard and exposure level.

Using the Periodic Table

Metals

• Conduct heat/electricity, malleable, shiny (e.g., Na, Fe, Cu).

Nonmetals

• Poor conductors, varied states (e.g., O, C, N).

Groups & Periods

• Group 1: Alkali Metals - highly reactive.

• Group 2: Alkaline Earth Metals - less reactive.

• Group 17: Halogens - highly reactive nonmetals.

• Group 18: Noble Gases - stable and non-reactive.

Energy, Wavelength, and Frequency of Light

• Light behaves as wave and particle; key equations relate energy, wavelength, and frequency.

Light Absorption in Lab #5

• Chlorophyll absorbs red/blue light, reflects green.

• Ozone absorbs UV light, protects life from UV damage.

Greenhouse Gases

• CO₂, CH₄ absorb IR radiation; contributes to global warming.

The Ozone Layer

• Absorbs UV rays, located in the stratosphere; vital for life.

• CFCs damage ozone, creating thinning areas (ozone hole).

Ozone Depletion Effects

• Increased exposure to UV leads to health/environmental issues.

Chapman Cycle

• Natural ozone formation/destruction cycle disrupted by human-made chemicals (CFCs).

Major Treaty Addressing Ozone Depletion

• Montreal Protocol: Focusing on reducing ozone-depleting substances with successful outcomes.

Replacements for CFCs

• HFCs: Safer for ozone but potent greenhouse gases.

Global Climate Change Mechanisms

1. GHG absorb IR radiation due to molecular structure.

2. Rising CO₂ concentrations linked to temperature increases.

Impacts of Temperature Rise

• Increased extreme weather, ecosystem disruption, and economic strain.

Reducing Carbon Dioxide Emissions

• Transition to renewable energy, energy efficiency, carbon capture, sustainable practices.

Ecological Effects of Warming

• Melting glaciers, altered ecosystems, and ocean acidification.

Kyoto Protocol

• International treaty to reduce GHG emissions with mixed U.S. compliance.

Urban Heat Island Effect

• Higher temperatures in urban areas due to human activities.

Importance of Trees According to James Madison

• Emphasized trees' roles in maintaining environmental balance, predicting negative consequences of deforestation.