Antoine Lavoisier's Discovery (1772)
Showed that the total amount of substances remains constant during transformations—"Nothing is lost, nothing is created, everything is transformed."
Influence of Matter and Energy on Environmental Choices
Forest fires impact wildlife, air quality, respiratory health, and contribute to climate change by releasing CO2.
Importance of Understanding Matter and Energy
Critical for decision-making related to sustainability; knowledge helps identify sources of environmental problems and their solutions.
Definition of Matter
Matter: Anything that occupies space and has mass. Comes in various forms: solids, liquids, gases, living/nonliving, human-made.
Matter is finite and composed of atoms.
Elements and Atoms
Element: A substance that cannot be broken down (e.g., gold).
Of the 118 known elements, 90 exist in nature; others are lab-created.
Atom: The smallest unit of an element retaining the element's characteristics.
Protons
Positively charged particles; define the atomic number of an element.
Electrons
Negatively charged; orbit the nucleus in shells. An atom is electrically neutral if protons equal electrons. With an imbalance, it becomes an ion.
Neutrons
Neutral particles found in the nucleus.
Isotope: Variation of an element with a different number of neutrons (e.g., 15N vs. 14N).
Physical Properties Depend on:
The type of atoms involved, how they bond, and their arrangement.
Molecules and Compounds
Molecule: Two or more atoms bonded together (e.g., O2).
Compound: A molecule consisting of atoms from two or more elements (e.g., H2O).
Conservation of Mass
Law of conservation of mass: Matter cannot be created or destroyed; the mass remains unchanged despite chemical reactions and rearrangements of atoms.
Bonding and Molecular Properties
The arrangement and connection of atoms dictate the properties of substances.
Ionic Bond
Strong bond formed when one atom donates electrons to another.
Metallic Bond
Electrons shared among metal atoms, allowing for malleability and conductivity.
Covalent Bond
Bonds when pairs of atoms share electrons; examples include N2, O2, and H2O.
Hydrogen Bond
Weak bond between a hydrogen atom (slight positive charge) and another atom with a negative charge; water molecules bond through hydrogen bonds due to polarity.
Definitions:
Acids yield H+ ions in water; strong acids have higher concentrations than weaker ones.
Bases yield OH- ions in water; strong bases have higher OH- concentrations than weaker ones.
pH Scale:
pH = 7 is neutral; < 7 is acidic; > 7 is basic.
Small pH changes can significantly impact ecosystems (e.g., CO2 increasing lake acidity).
Types of Changes
Matter can experience physical changes (phase changes) or chemical changes (reactions).
Phase Change
Change in state (solid, liquid, gas) without altering chemical composition.
Molecular Movement
Solids: Atoms vibrate slowly in fixed shapes; attractively bonded.
Liquids: Atoms vibrate faster; have constant volume but adaptable shapes.
Gases: Atoms vibrate rapidly and randomly; no fixed volume or shape.
Chemical reactions allow molecules to convert into new substances.
Oxidation-reduction reactions (redox): involve electron transfer (oxidation = electron loss; reduction = electron gain).
Examples: Sugar oxidation in cells for energy production.
Polymerization: Smaller molecules link to form larger structures.
Depolymerization: Breaking down of biopolymers (e.g., marinating meat).
Energy: Capacity to do work (applying force over distance).
Kinetic Energy
Energy of motion (e.g., moving bird, car, rock).
Potential Energy
Stored energy (e.g., water in a dam, rock on a cliff).
Mechanical Energy
Can move objects, push, pull, or exert force.
Chemical Energy
Stored within atomic bonds; released during reactions (e.g., glucose).
Electrical Energy
Produced by moving electrons in conductive materials.
Radiant Energy
Energy from the sun; initiates photosynthesis in plants, algae, and some bacteria.
Nuclear Energy
Energy stored in atomic nuclei; includes nuclear fusion (fusing nuclei) and fission (splitting nuclei).
Geothermal Energy
Energy from Earth's core powering global processes.
Energy, like matter, is constant.
First Law
Energy cannot be created or destroyed; it can change forms.
Second Law
Energy transformations always degrade some energy (heat loss); leads to increasing entropy without energy input.
Food Chains and Trophic Levels
Organisms categorized by trophic levels—their position in the food chain.
Descriptions of levels: Primary producers (photosynthesis), primary consumers (herbivores), secondary consumers (carnivores/omnivores), tertiary consumers (meat-eaters), and decomposers.
The 10% Law
Only 10% of energy transfers from one trophic level to the next; the rest is lost to heat, waste, and respiration.
Higher trophic levels require more energy for biomass compared to lower levels.
Understand and Promote Sustainability
Research companies with sustainable practices; advocate for environmentally friendly policies.
Volunteer for Sustainability Initiatives
Engage with your school’s Office of Sustainability.
Adopt Recycling Practices
Utilize recyclable materials (steel, paper, plastic).
Make Sustainable Choices
Avoid products with pollutants; opt for sustainable alternatives.
Innovate in Sustainability
Explore opportunities in green business and practices.