Ecosystems, Matter, and Chemical Properties: Key Concepts

Biotic and Abiotic Factors in an Ecosystem

• Chemistry: The study of matter.
• Matter: Any substance that has mass and takes up space.
• Energy: The capacity of a physical system to do work.
• Ecosystem: All of the living things in a given area.
• Biotic: Living organisms (e.g., flowers, plants, bacteria).
• Abiotic: Non-living organisms (e.g., water, soil, air, light, wind).

States of Matter

• Solids: More dense, particles are very close, molecules only vibrate, cannot flow, defined shape, defined volume, not compressible.
• Liquids: Dense, particles are close, molecules have random flow, can flow, adaptable shape, defined volume, very little compressible.
• Gas: Less dense, particles are separated, molecules have a random, fast, and free movement, can flow, no shape, no defined volume, highly compressible.
• Deposition: Gas to solid.
• Deionization: Plasma to gas.
• Sublimation: Solid to gas.
• Ionization: Gas to plasma.
• Condensation: Gas to liquid.

Physical and Chemical Changes of Matter

• Physical: A type of change in which the form of matter is altered, but one substance is not transformed into another.
• Chemical: A process where one or more substances are altered into one or more new and different substances.

Physical and Chemical Properties of Matter

• Physical: A characteristic of matter that may be observed and measured without changing the chemical identity of a sample.
• Chemical: A characteristic or behavior of a substance that may be observed when it undergoes a chemical change or reaction.

Classification of Matter

• Pure Substances: Elements and compounds.
• Mixtures:
  • Homogeneous: Only one phase of matter is observed (e.g., air, sugar water, rainwater, vodka, vinegar, dishwashing detergent, steel).
  • Heterogeneous: Two or more phases are present (e.g., cereal in milk, vegetable soup, pizza, blood, gravel, ice in soda).

Methods for Separating Mixtures

• Decanting: Done to separate particulates from a liquid by allowing the solids to settle to the bottom of the mixture and pouring off the particle-free part of the liquid (solid to liquid / two liquids).
• Filtration: Separates solids from liquids.
• Sieving: Used to separate solids from liquids by means of a strainer.
• Centrifugation: Separates blood, DNA, or proteins.
• Magnetization: Fe-Co-Ni.
• Deposition: The settling of particles or sediment onto a surface. The particles may originate from a vapor, solution, suspension, or mixture.
• Distillation: Used to separate a solid from a liquid, or two liquids with different boiling points.
• Crystallization: Used to recover a solid dissolved in water.
• Adsorption: Used to remove color, odor, or pollutants from water, food, or air.
• Extraction: Used to recover a component from a solid mixture.
• Chromatography: Used to separate colored substances like ink and chlorophyll.