Test #1 Notes – Con’t Concept Map #2 Classification of Matter

The Phases (States) of Matter Solid (s) * definite shape & definite volume * particles are in a regular, geometric pattern or crystalline shape * particles vibrate in fixed positions Liquid (l) * take shape of container, definite volume * particles can flow Gas (g) * expand to completely fill container * no definite shape or volume Note - Vapor refers to a substance that is not normally a gas. (aq) = Aqueous = the substance is dissolved in water.

Phases – con’t 4. The phases differ due to differences in the: a) arrangement or distance between their particles b) attraction between their particles. http://www.youtube.com/watch?v=s-KvoVzukHo&feature=related Solid Liquid Gas

The Three Classes of Matter: Elements Compounds Mixtures Matter Substance Mixtures of Substances (fixed composition) (composition varies) Elements Compounds Heterogeneous Homogeneous (these are homogeneous) Suspensions Solutions

Models Elements (made of a single kind of atom) Monatomic Element or Diatomic Element He H2 Compounds (hook different atoms together to show they are chemically combined) Water is a compound (H2O) Mixtures (the different substances aren’t hooked – shows they are physically combined) Mixture of Water (H2O) & Oxygen (O2)

Elements 1. Elements are substances composed of atoms that cannot be broken down any further. A particular element contains atoms having the same atomic number. Some examples: Iron (Fe) or Hydrogen (H2)

Elements – con’t Some elements exist in several different forms. They have different structures & different properties. (Allotropes) Example: Forms of solid Carbon

Elements – con’t Example: Forms of Oxygen gas Most oxygen in the air is O2. This is the odorless gas that sustains life. Ozone is O3. Ozone gas has a sharp odor and damages respiratory tissue.

Compounds 1. Compounds are substances composed of atoms from 2 or more different elements chemically combined in a fixed or definite ratio. 2. The compound’s properties are not the same as its component’s original properties. Examples: Water (H2O) Sodium Chloride (NaCl)

Mixtures Mixtures are composed of 2 or more different substances physically combined in any ratio. The composition of a mixture is not fixed. For example grape juice may be really sweet or tart. The components of a mixture keep (or retain) their original individual properties. Examples: Raisin Bran, Chex Mix, Koolaid, Italian Salad Dressing

E, C, or M? NH3(g) Br2(l) H2SO4(aq) Cu(s) NaCl(s) NaCl(aq) Answers: C, E, M, E, C, M

Homogeneous Mixtures You cannot see the different parts because the particles are uniformly or evenly mixed resulting in constant properties throughout that sample. Examples: Kool-Aid, Air, Milk, Saltwater.

Heterogeneous Mixture You can see visibly different parts because the particles are NOT uniformly mixed. Examples: Soil, Vegetable soup, Trail mix, Lucky charms

Miscible vs Immiscible Miscible refers to mixtures of liquids that dissolve in each other Example: water & vinegar Immiscible refers to mixtures of liquids that separate (don’t dissolve) Example: water & oil

Solutions A solution is a homogeneous mixture containing a solute dissolved in a solvent. Example: sugar water C12H22O11 (aq) (aq) = aqueous = dissolved in water 2. The solute (sugar) is the substance dissolved. 3. The solvent (water) does the dissolving. They cannot be separated by filtration. Note: If a solid dissolves, we say it is soluble.

Suspensions A suspension is a heterogeneous mixture of an insoluble solid suspended in a liquid. The insoluble solid doesn’t dissolve, it will settle on standing. An example is cornstarch mixed in water. They can be separated by filtration.

Separation of Mixtures The components in a mixtures can be separated physically - based on differences in properties such as color, density, solubility, etc. Some examples: (see pictures) Filtration (particle size) Chromatography (absorption) Distillation (boiling point)

Filtration In filtration, larger solid particles are separated from smaller liquid particles by passing the mixture through a filter. http://www.youtube.com/watch?v=P6yhfd2i0cw&feature=relmfu

Distillation Distillation uses differences in the boiling points to separate a homogeneous mixture into its components. http://www.youtube.com/watch?v=xxNfJLMNS4E

Chromatography Separation of components of black ink Chromatography separates substances in a mixture based on differences in absorption up a strip of paper dipped in a solvent. http://www.youtube.com/watch?v=08YMBGS1pYU

Separation of Compounds Occurs only by chemical reaction Example: Decomposition of water into hydrogen and oxygen gas http://www.youtube.com/watch?v=EE58a5fN468