1. Classification of Matter

2. Pure Substances Element –composed of identical atoms –EX: copper wire, aluminum foil Courtesy Christy Johannesson www.nisd.net/communicationsarts/pages/chem

3. Pure Substances Compound –composed of 2 or more elements in a fixed ratio –properties differ from those of individual elements –EX: table salt (NaCl) Courtesy Christy Johannesson www.nisd.net/communicationsarts/pages/chem

4. Pure Substances Law of Definite Composition –A given compound always contains the same, fixed ratio of elements. Law of Multiple Proportions –Elements can combine in different ratios to form different compounds. Courtesy Christy Johannesson www.nisd.net/communicationsarts/pages/chem

5. Pure Substances For example… Two different compounds, each has a definite composition. Carbon, C Oxygen, O Carbon monoxide, CO Carbon, C Oxygen, O Oxygen, O Carbon dioxide, CO 2 Courtesy Christy Johannesson www.nisd.net/communicationsarts/pages/chem

6. MATTER Can it be physically separated? CompoundElement PURE SUBSTANCE no Can it be chemically decomposed? noyes Courtesy Christy Johannesson www.nisd.net/communicationsarts/pages/chem

7. Mixtures Variable combination of 2 or more pure substances. HeterogeneousHomogeneous Courtesy Christy Johannesson www.nisd.net/communicationsarts/pages/chem

8. Mixtures Solution –homogeneous –very small particles –no Tyndall effect Tyndall Effect –particles don’t settle –EX: rubbing alcohol Courtesy Christy Johannesson www.nisd.net/communicationsarts/pages/chem

9. Mixtures Colloid –heterogeneous –medium-sized particles –Tyndall effect –particles don’t settle –EX: milk Courtesy Christy Johannesson www.nisd.net/communicationsarts/pages/chem

10. Mixtures Suspension –heterogeneous –large particles –Tyndall effect –particles settle –EX:fresh-squeezed lemonade Courtesy Christy Johannesson www.nisd.net/communicationsarts/pages/chem

11. Classification of Matter Materials Homogeneous Heterogeneous mixture Homogeneous mixture Substance ElementCompoundSolutionMixture Specific / General Order / Disorder Smoot, Smith, Price, Chemistry A Modern Course, 1990, page 43

12. MATTER Can it be physically separated? Homogeneous Mixture (solution) Heterogeneous MixtureCompoundElement MIXTUREPURE SUBSTANCE yesno Can it be chemically decomposed? noyes Is the composition uniform? noyes ColloidsSuspensions Courtesy Christy Johannesson www.nisd.net/communicationsarts/pages/chem

13. Elements, Compounds, and Mixtures (a) an element (hydrogen) (b) a compound (water) (c) a mixture (hydrogen and oxygen) (d) a mixture (hydrogen and oxygen) Dorin, Demmin, Gabel, Chemistry The Study of Matter, 3 rd Edition, 1990, page 68 hydrogen atoms hydrogen atoms oxygen atoms

14. Matter Flowchart Examples: –graphite –pepper –sugar (sucrose) –paint –soda element hetero. mixture compound hetero. mixture solution Courtesy Christy Johannesson www.nisd.net/communicationsarts/pages/chem

15. Elements, Compounds, and Mixtures (a) an element (hydrogen) (b) a compound (water) (c) a mixture (hydrogen and oxygen) (d) a mixture (hydrogen and oxygen) Dorin, Demmin, Gabel, Chemistry The Study of Matter, 3 rd Edition, 1990, page 68 hydrogen atoms hydrogen atoms oxygen atoms

16. Matter Substance Definite composition (homogeneous) Substance Definite composition (homogeneous) Element (Examples: iron, sulfur, carbon, hydrogen, oxygen, silver) Element (Examples: iron, sulfur, carbon, hydrogen, oxygen, silver) Mixture of Substances Variable composition Mixture of Substances Variable composition Compound (Examples: water. iron (II) sulfide, methane, Aluminum silicate) Compound (Examples: water. iron (II) sulfide, methane, Aluminum silicate) Homogeneous mixture Uniform throughout, also called a solution (Examples: air, tap water, gold alloy) Homogeneous mixture Uniform throughout, also called a solution (Examples: air, tap water, gold alloy) Heterogeneous mixture Nonuniform distinct phases (Examples: soup, concrete, granite) Heterogeneous mixture Nonuniform distinct phases (Examples: soup, concrete, granite) Chemically separable Physically separable

17. The Organization of Matter MATTER PURE SUBSTANCES HETEROGENEOUS MIXTURE HOMOGENEOUS MIXTURES ELEMENTSCOMPOUNDS Physical methods Chemical methods Zumdahl, Zumdahl, DeCoste, World of Chemistry  2002, page 41

18. Top Ten Elements in the Universe Percent Element (by atoms) 1.Hydrogen73.9 2.Helium24.0 3.Oxygen 1.1 4.Carbon 0.46 5.Neon 0.13 6.Iron 0.11 7.Nitrogen 0.097 8.Silicon 0.065 9.Magnesium 0.058 10.Sulfur 0.044 A typical spiral galaxy (Milky Way is a spiral galaxy) Zumdahl, Zumdahl, DeCoste, World of Chemistry  2002, page 26

19. The Composition of Air Air Nitrogen Oxygen Helium Water vapor Water vapor Neon Carbon dioxide Carbon dioxide Argon Zumdahl, Zumdahl, DeCoste, World of Chemistry  2002, page 34

20. Chart Examining Some Components of Air Nitrogen consists of molecules consisting of two atoms of nitrogen: Oxygen consists of molecules consisting of two atoms of oxygen: Water consists of molecules consisting of two hydrogen atoms and one oxygen atom: Argon consists of individual argon atoms: Carbon dioxide consists of molecules consisting of two oxygen atoms and one carbon atom: Neon consists of individual neon atoms: Helium consists of individual helium atoms: N2N2 O2O2 H2OH2O Ar CO 2 Ne He Zumdahl, Zumdahl, DeCoste, World of Chemistry  2002, page 35

21. Reviewing Concepts Classifying Matter Why does every sample of a given substance have the same properties? Explain why the composition of an element is fixed. Describe the composition of a compound. Why can the properties of a mixture vary? On what basis can mixtures be classified as solutions, suspensions, or colloids?

22. MATTER Can it be physically separated? Homogeneous Mixture (solution) Heterogeneous MixtureCompoundElement MIXTUREPURE SUBSTANCE yesno Can it be chemically decomposed? noyes Is the composition uniform? noyes ColloidsSuspensions Courtesy Christy Johannesson www.nisd.net/communicationsarts/pages/chem