Ecosystem Dynamics and Sustainability Quiz

Chemical Reactions

• A chemical reaction is a change in the chemical properties of a substance, creating a new substance.
• The International Hazard System uses symbols to indicate the level of danger. There are only four symbols: poison, flammable, explosive, and corrosive.
• The Workplace Hazardous Materials Information System (WHMIS) uses ten symbols to identify hazards including flame, skull & crossbones, biohazardous, health hazard, flame over circle, exploding bomb, gas cylinder, corrosion, exclamation mark, and environment. WHMIS labels provide more detail.

Endothermic/Exothermic Reactions

• Endothermic: Absorbs heat, causing the surroundings to cool. Energy is absorbed.
• Exothermic: Releases heat, causing the temperature of the surrounding to rise. Energy is released.

Indicators of Chemical Reactions

• Five indicators of chemical reactions are:
  • Colour change
  • Odour/gas production
  • Temperature change
  • Heat/light production
  • Precipitate formation

Other Concepts

• Observations: Collecting data using the senses.
• Products: Substances formed in a chemical reaction.
• Reactants: Substances undergoing a change in a chemical reaction.
• Anion: Negatively charged ion.
• Cation: Positively charged ion.
• Balanced Chemical Equations: Represent reactants and products in a reaction, with the total number of each atom remaining the same.
• Binary Compound: A compound with two different elements.
• Chemical Equation: Describes the actual change in a material during a chemical reaction.
• Covalent Bond: Atoms share electrons to form a bond.
• Diatomic Molecule: Molecule containing two identical atoms.
• Ion: An atom that has gained or lost electrons.
• Ionic Bond: Transfer of electrons between a metal and a non-metal.
• Ionic Compound: When a metal and non-metal bond.
• Law of Conservation of Mass: Total mass of reactants equals total mass of products.
• Molecular Compound: A neutral compound made up of two or more non-metals bonded covalently.
• Polyatomic Ion: Ion consisting of two or more non-metal atoms bonded covalently.
• Scientific Law: A statement that summarizes a fully proven observed pattern in nature.
• Valence Electrons: Electrons in the outer ring of an atom.
• Word Equation: Describes reactants, products, and states of matter in a reaction using words.
• Combustion: The rapid reaction of oxygen with another substance, producing oxides and energy.
• Hydrocarbons: Compounds containing only hydrogen and carbon.
• Incomplete Combustion: Combustion without enough oxygen.
• Organic Compounds: Molecular substances that contain carbon.
• Catalyst: Changes the rate of a chemical reaction without being changed itself.
• Collision Model: Reaction rate is affected by the number of collisions between reactant molecules.
• Interpreting Data: Finding patterns in data, leading to greater generalizations.
• Scientific Knowledge: Based on observation and experimentation.
• Factors Affecting Reaction Rate: Nature of reactants, temperature, pressure, concentration, surface area, catalyst.
• Acids: Substances with a pH less than 7, produce H+ ions in water, sour taste, good conductors, turn blue litmus paper red. They react with bases to produce salt and water.
• Bases: Substances with a pH more than 7, produce OH- ions in water, bitter taste, good conductors, slippery feel, turn red litmus paper blue. React with acids to produce salt and water.
• Neutral Substance: A substance with a pH of 7 (neither acidic or basic).
• Neutralization: Reaction between an acid and a base produces salt and water.
• pH Scale: Measures acidity or alkalinity of a solution, a change of 1 pH unit represents a tenfold change in acidity or alkalinity
• Salt: An ionic compound composed of a cation (from a base) and an anion (from an acid).
• pH Scale Measures: The presence of hydrogen ions.
• Hypothesizing: Using a tentative generalization to explain events.
• Controlling Variables: Isolating factors that may influence the outcome of an experiment.
• WHMIS & MSDS: Workplace Hazardous Material Information System and Material Safety Data Sheets, that provide safety and health information on materials.

Safety Procedures

• Lab Safety Rules for working with chemicals in a laboratory.

Definitions

• Biome: Large area with specific climate, vegetation, and animal life.
• Biosphere: The area around Earth where life exists.
• Biodiversity: Measure of the number and variety of species in an ecosystem.
• Biotic Potential: Maximum number of offspring a species could produce if resources were unlimited.
• Carrying Capacity: Maximum number of individuals that an ecosystem can support.
• Mortality: Death rate in a population.
• Natalitly: Birth rate in a population.
• Immigration: The movement of individuals into a population.
• Emigration: The movement of individuals out of a population.
• Closed System: One in which individuals cannot enter or leave.
• Open System: One in which individuals can enter or leave.
• Limiting Factors: Factors that regulate the size of populations.
• Density-dependent Limiting Factors: Limiting factors that affect population size when density increases.
• Density-independent Limiting Factors: Limiting factors that do not depend on population density.
• Autotroph: A producer – makes its own food.
• Heterotroph: A consumer – obtains energy by consuming other organisms.
• Trophic Level: Position within a food chain/web or energy pyramid.
• Food Chain: Path of energy flow from producer to consumer.
• Food Web: Interconnected set of food chains.
• Biomass: The dry mass of organic matter in a group of living things.
• Pyramid of Energy: Shows the amount of energy at each trophic level.
• Pyramid of Numbers: Shows the number of organisms at each trophic level.
• Pyramid of Biomass: Shows the dry mass of organisms at each trophic level.
• Nutrient: Substances an organism needs for growth, repair, and function (e.g., nitrogen, oxygen, carbon, water, phosphorus, sulfur, hydrogen).
• Biogeochemical Cycle: The path of a nutrient in an ecosystem.
• Bioaccumulation: Increase in concentration of a pollutant in organisms.
• Biomagnification: Increase in pollutant concentration as energy transfer proceeds through trophic levels.
• Cellular Respiration: Process where organisms break down glucose to release energy in the presence of oxygen.
• Photosynthesis: Process where plants use carbon dioxide, water, and light to produce glucose, producing oxygen.
• Nitrogen Cycle: Series of processes that transforms nitrogen in the atmosphere into usable forms for organisms.
• Nitrification: Conversion of ammonia to nitrites & then nitrates.
• Denitrification: Conversion of nitrates back into nitrogen gas (releasing nitrogen into atmosphere).

Climate & Ecosystems

• Sustainability: Ability to meet the needs of the present without compromising future generations' ability to meet their needs.
• Ecological Footprint: Measure of an individual's or population's environmental impact.
• Human Impact: Environmental effect of human lifestyles, discoveries, and developments.
• System: Interrelated components.
• Ecosystem: Collection of living (biotic) and nonliving (abiotic) components in an area and their relationships.
• Abiotic: Non-living things

Forces & Motion

• Position: An object's location.
• Direction of Motion: The path an object follows.
• Speed: How fast an object is moving.
• Science: Systematic knowledge gained through observation, experimentation, and predictions.
• Technology: Applying scientific and technical knowledge.
• Frame of Reference: Point of comparison when determining motion.
• Uniform Motion: Constant speed in a straight line.
• Rate of Change: How quickly a quantity changes over time.
• Position: An object's location.
• Distance: Length of the path travelled.
• Speed: Rate of change of distance; speed = distance/time.
• Instantaneous Speed: Speed at a specific moment in time.
• Average Speed: Average rate of change of distance over an interval of time.
• Acceleration: Rate of change of speed.
• Models: Simplified representation of real phenomena.
• Hypothesizing: Making a prediction that can be tested.