Composition of Matter Flashcards

Composition of Matter

• Element: A pure substance consisting solely of one type of atom; basic building blocks of matter.
• Atom: The fundamental unit of matter, indivisible in chemical processes; cannot be created or destroyed easily.
• Compound: Formed when two or more elements chemically bond together, resulting in a substance with distinct properties.
• Molecule: The smallest unit of a compound, maintaining its chemical properties; determined by the bonding of atoms.
• Mixture: A combination of two or more substances where each retains its individual properties; composition is variable.

Laws and Changes

• Law of Conservation of Matter: States that matter cannot be created or destroyed in a chemical reaction; mass remains constant.
• Chemical Change Characteristics: Indicators include color change, gas production, temperature fluctuations, and changes in odor.
• Physical Change: Alterations in a substance's physical attributes like size, shape, or color, without altering its chemical composition; includes changes in state (solid, liquid, gas).

Examples of Changes

• Physical Change Examples: Melting of ice, mixing sulfur with iron filings, breaking glass, or dissolving sugar in water.
• Chemical Change: Involves the formation of new substances through atomic rearrangement; such changes are typically irreversible.
• Chemical Change Examples: Burning magnesium creates white ash (MgO), reacting zinc with hydrochloric acid, and metabolic processes in the body.

Mixtures and Solutions

• Heterogeneous Mixture: Contains visibly different substances or phases; components are not uniformly distributed.
• Homogeneous Mixture: Exhibits consistency throughout; considered a solution where the components are evenly distributed.
• Solution: A homogeneous mixture of two or more substances, which can exist in solid, liquid, or gaseous forms.

Purity and Concentration

• Pure Substance: Defined by a constant and uniform composition, with consistent properties throughout.
• Concentration Equation: Expressed as Concentration = Mass/Volume; used to determine the concentration of solutions.

Separation Techniques

• Distillation: A separation process involving boiling liquids to isolate a substance with a higher boiling point.
• Filtration: Utilizes a filter to separate solid particles from liquids or gases.
• Decantation: Involves carefully pouring off liquid from settled solids or denser liquids.
• Magnetism: A method of separating magnetic metals from non-metallic substances using a magnet.