Pure substances and mixtures: Diatomic Elements: HOFBrINCl. Here are concise definitions and examples for each term. Matter: Anything that has mass and occupies space. Example: Wat... Pure substances and mixtures: Diatomic Elements: HOFBrINCl. Here are concise definitions and examples for each term. Matter: Anything that has mass and occupies space. Example: Water, air, and a rock are all matter. Pure Substance: A material with a constant composition, distinct chemical properties, and cannot be separated. Example: Pure distilled water (H₂O). Element: A substance made of only one type of atom, which cannot be broken down into simpler substances. Example: Oxygen (O₂). Compound: A substance formed when two or more elements chemically bond together in a fixed ratio. Example: Carbon dioxide (CO₂). Mixture: A combination of two or more substances that are not chemically bonded, retain their individual properties, and can be separated. Example: Salt and sand mixed together. Homogeneous Mixture: A mixture with a uniform composition throughout, where the different components are not distinguishable. Example: Salt dissolved in water (saltwater). Heterogeneous Mixture: A mixture where the components are not uniformly distributed, and individual substances are easily distinguishable. Example: A salad with lettuce, tomatoes, and cucumbers. Ways to separate matter: filtration, distillation, chromatography. Filtration: Used to separate a heterogeneous mixture of a solid and liquid. Ex: CaCO3 and water. Distillation: Used to separate a homogeneous mixture of a liquid and liquid using difference in boiling point. Ex: ethanol and water. Chromatography (know the difference): Used to separate complex mixtures using columns, paper or special plates. Column chromatography: depending on how fast or slow fluids go through, you can separate the layers. Paper chromatography: When you drop the paper in and the water sinks through, and it depends on how fast or slow the ink bleeds. You can measure and see where the colors are. Thin-layer chromatography: You put a small spot of the mixture on the TLC plate (which is like a piece of paper). When you dip the bottom of the plate in the solvent (like water or alcohol), the solvent starts moving up the plate. The substances in the mixture move with the solvent, but some stick to the plate more and move slowly, while others stick less and move faster. This causes the different substances to spread out and separate into distinct spots on the plate. Read more