Classifications and Phases of Matter

Classifications of Matter

• A mixture has varying compositions.
• A pure substance has a uniform composition.
  • A heterogeneous mixture has components that can still be identified. Examples include garden salad and trail mix.
  • A colloid has observed properties of a homogeneous mixture but is heterogeneous when subjected to certain tests. Examples include milk and styling gel.
  • A homogeneous mixture (solution) has a very uniform composition. Examples include brine (saltwater) and orange juice drink.
• A pure substance can be classified into two categories:
  • An element consists of only one kind of atom. Examples include Ds (Darmstadtium) and H (Hydrogen).
  • A compound is a substance composed of molecules, a combination of atoms from two or more elements. Examples include Aqua Fortis (HNCO3) and water (H2O).

Phases of Matter

• Solids have a defined appearance, own shape, and very little to no molecular movement. They exhibit a rigid molecular structure. Example: diamond.
• Liquids have molecular movement, no shape of their own, and take the shape of their container. Example: a glass of lemon juice.
• Gases have high molecular movement, have a looser molecular structure than liquids, and behave the same way as liquids. Example: the air we breathe.
• Plasma has very high molecular movement due to the absorption and release of energy, causing molecules to move faster. High-temperature plasmas glow a certain color. Example: neon light fixtures.

Phase Transitions in Matter

• Melting is the process of adding heat to a solid, causing it to become a liquid. Example: scraps of iron (Fe) bars melted to be reformed into solid iron blocks.
• Evaporation is the process of adding heat to a liquid, causing its loose molecular bonds to break further and turn into a gas. Example: Saltwater (NaCl (aq)) is made to evaporate in a saltwater flat to extract salt (NaCl (aq) → NaCl + H2O↑).
• Ionization is the process of adding heat to a gas, adding energy to it, and charging the molecules into ions (plasma is made up of ions). Example: Energy is added in a glass tube filled with Neon (Ne), making the Neon gas glow due to the ionization process.
• Recombination is the process of removing heat in a plasma, returning the ions to a ground state, and becoming a gas (sometimes called deionization). Example: Neon plasma deionizes back to its gaseous form once it begins to cool.
• Condensation is the process of transferring energy in gas molecules to the surrounding area, forcing the gas molecules to form bonds and coalesce into a liquid. Example: Water vapor condenses back to liquid water to form clouds.
• Freezing is the process of transferring heat in liquids to the surrounding area, forcing the molecules to reform and bond into a solid. Example: Liquid Mercury (Hg), poured into a mold, is solidified when poured with liquid nitrogen (N2 (aq)).
• Sublimation is the process of adding energy to a solid, causing it to dissipate into a gas without transitioning to the liquid phase. Example: Frozen carbon dioxide (CO2) sublimates into carbon dioxide gas (CO2↑) when exposed to room temperature.
• Deposition is the process of transferring energy from gas molecules to the surrounding area, forcing them to combine and make “deposits” of clumped gas molecules together, reforming into a solid. Example: Water vapor (H2O↑) deposits itself as ice crystals (H2O) when forming snowflakes.

Properties of Matter

• Physical properties of matter can be quantified using measurements and assessed by the five senses. Examples include mass, color, and length.
• Chemical properties are assessed from the material's chemical structure, processes, and results. Examples include flammability, toxicity, and enthalpy (total heat content in a system).
• Extensive properties depend on the material's physical properties. If any physical property changes in a material, its extensive properties change accordingly. Examples include mass, area, and length.
• Intensive properties are independent of the material's physical properties. Examples include color, temperature, and density.

Consumer Products

• Food Additives are substances added to food and/or beverages to improve flavor and appearance. They are also used to preserve the natural taste of food.
• Active Ingredients are substances that are biologically active. They are used mostly in pharmaceutical drugs and commodities like soap, powders, and others.
• Cleaning Agents are substances used to remove dirt, dust, stains, clutter, and foul odor. They may also kill some harmful microorganisms in the cleaning process.
• Cosmetics are substances that enhance the consumer's appearance and improve their fragrance.

This quiz covers the classifications of matter, including mixtures and pure substances, as well as the different phases of matter. You'll learn to differentiate between heterogeneous and homogeneous mixtures, as well as elements and compounds. Test your understanding of these key concepts in chemistry.