This document discusses several key chemistry concepts: 1) Molecular and ionic substances dissolve differently, with molecular substances dissolving as molecules and ionic substances dissolving as individual ions. 2) Ionic substances are composed of ions, often a metal and non-metal or polyatomic ion like NaCl or Na2SO4. 3) Electrolytes dissolve as individual ions in water. 4) Physical properties can be observed without changing the substance's composition, while chemical properties involve changes in composition through chemical reactions.

3. Solutions Dissolve as Individual particles Molecular Substances Dissolve as Molecules Molecular Substances Are composed Of non-metals

4. Ionic substances Are composed of Ions Often a metal + non-metal Or poly atomic ion NaCl Na2SO4 Dissolve as individual ions Electrolytes Recurrent theme!!!

5. All living things are heterogeneous

8. Review

9. Physical properties Observed without converting to another substance Intensive – characteristic of the substance Extensive – depends on amount of substance present (mass and volume most important!) Change of state – physical change – no change in Composition – ice  liquid water  water vapor – still H2O Other examples: hardness, mp bp, solubility, density, viscosity, color, taste, Smell (senses) –intensive

10. Chemical properties Relates to reactions of the substance Rx change composition of substance

11. Chemical properties describe how it can change into other substances In a chemical change – atoms rearrange to form new substances with new chem/phy properties What does it react with O2, acids, bases, oxidizers, reducers Does it rust, tarnish or combust?

12. Atoms rearranging

15. Physical vs Chemical Changes

16. SEPARATIONS Using differences in physical properties to separate pure substances in mixtures Bp, mp, solubility, magnetism Pasteur – crystal separation

17. Difference in bp’s

19. Paper chromatography Analogy of Racing through Downtown With free beer stops

20. Aug ’07 news article Cat in nursing home Curled up with dying Patients – How did it know? Metabolites in breath May be used to help Diagnose internal Infections/cancers!! What common breath test is frequently used? What condition can a nurse diagnose by smell of breath?

21. Coffee filter chromatogram --assignment

22. Temperature Temperature – degree of hotness or coldness! Intensity of energy Heat – energy – depends on Temperature Mass Type of substance Equal masses of water and oil on similar burners, similar time – temp??

23. Temperature scales What scales are you familiar with How many degrees between fp and bp water in oF…. oC 2 patients are sick A) 1o F fever B) 1o C fever Which is sicker???

24. Fever Why?? Infection fevers Are not likely to Cause “heat stroke “Heat stroke” Overheating Core body temps Fevers: adults vs Infants…

26. practice Sig fig – ans should have same number of decimal places!!!