2. Matter: It’s what the world’s made of.

3. Chemistry Studies Matter- Branches of Chemistry Organic Study of most carbon-containing compounds Basis for most life processes as well as plastics, drugs, petrochemicals, food, etc. Inorganic Study of non-organic substances Physical Study of properties and changes of matter and their relation to energy Analytical- identification of the components and composition of materials Biochemistry- study of substances and processes occurring in living things Theoretical- use of math and computers to provide theories that explain chemical observations; predict properties of new compounds

4. Chemistry Studies Properties Extensive properties depend on amount of matter present volume, mass, and amount of energy present Intensive properties independent of the amount present boiling point, melting point, density, conducting electricity and energy, phase change energy and others

5. States of Matter Solid – Definite shape and volume Liquid – Definite volume but variable shape Assumes the shape of its container Gas – Neither definite shape or volume Expands to fill any size container Takes the shape of the container Plasma – Extremely high energy state where electrons have been ejected

6. Changes of State Melting Freezing Vaporizing Boiling- change from liquid to vapor within the liquid as well as at the surface Evaporation- change from liquid to gas at the surface of the liquid; occurs at much lower temperatures than boiling Condensing Sublimation- example: dry ice (CO 2 ) Deposition- example: frost forming on a cold surface

7. What is Matter made of? Elements Compounds Mixtures See classification scheme for matter on p.11 of the text

8. What is Matter made of? Elements-cannot be broken down Atomic-most elements can exist as individual atoms(smallest particle of any element). Examples: Fe, Au, Ag, Al Molecular-some elements are… Diatomic H 2, O 2, N 2, F 2, Cl 2, Br 2, I 2 Triatomic O 3 Tetratomic P 4 Octatomic S 8 Elements are found on Periodic Table

9. What is Matter made of? Compounds-Two or more elements chemically bonded together These can be broken down into smaller compounds or elemental parts Examples: CaCO 3 (chalk), Fe 2 O 3 (rust) Smallest particle is a Molecule

10. Pure Substances Always have a fixed composition Can be elements or compounds Always have the same properties Always have the same composition Pure water is always 11.2% Hydrogen and 88.8% Oxygen by mass

11. What is Matter made of? Mixtures-These are made of two or more chemicals that are not chemically bonded together. Examples: Sand, Salt/Pepper, Milk, Blood, Muddy water Homogeneous – uniform throughout Heterogeneous – differences are found Mixtures can often be separated easily by physical means such as filtration, distillation or chromatography.

12. Filtration: Separates solid substances from liquids and solutions. Coffee Filters Some water filters Pool filters using sand or DE- diatomaceous earth (spongy skeleton)

13. Distillation: Separates Homogeneous mixtures using the differences in boiling points. BP H20 = 100˚C BP NaCl = 808˚C Water vapor rises first and condenses in the tube.

15. Chromatography: Separates substances on the basis of differences in solubility in a solvent.

16. Classification Flowchart

17. Physical Properties Observed without changing the identity of a substance Volume, mass, size, color, shape, smell, hardness, density, texture, melting & boiling points, temperature…

18. Physical Changes Change that alters appearance or form of material but does not change the identity of the substance Examples: tearing paper, breaking pencil, ice melting Phase changes are ALWAYS Physical Changes

19. Chemical Properties Substances ability to undergo changes that transform it into different substances (with different properties) Does it react with Oxygen? Does it react with Water? Does it react with Chlorine? Does it react with Fluorine? Does it react with …?

20. Chemical Changes A chemical reaction occurs that produces NEW substances Old chemicals bonds(Reactants) must be broken and new ones(Products) formed usually with energy exchanging Example: burning fuel, digesting food, Photosynthesis, rusting iron, plant decay, baking cookies

21. Demo/Activity Chemical change or physical change?

22. 2 Kinds of Chemical Reactions Exothermic Releases heat into surroundings Might feel warm or hot to the touch Reactants have higher energy in their bonds Examples: Mixing acid with bases Burning of a fuel Digestion

23. 2 Kinds of Chemical Reactions Endothermic Absorbs heat from the surroundings Could feel cool to the touch Products have more energy than reactants Examples: Cooking an egg Dissolving Baking Soda Photosynthesis Cooking coffee beans

24. Demo Exothermic Calcium chloride and sodium bicarbonate with water Endothermic Ammonium chloride and water (dissolution of sodium chloride)

25. Chemical Equations 2 H 2 (g) +O 2 (g)  2 H 2 O(l) + Energy Coefficients  “yields” (s), (g), (l) Energy is always involved-Heat or Light Exothermic Endothermic Balancing will follow later Matter CANNOT be created or destroyed but it can be changed in reactions

26. Measurements are wrong! Measurements are not pure numbers Measurements are made by man using instruments made by man and subject to error UNCERTAINTY FACTORS 345±2ml Every measuring device has an UF Usually ½ of the smallest readable graduation

27. Instrument Reading Instrument reading is critical in Science Expected accuracy is based on the divisions provided by the instrument and the Uncertainty Factor (to be discussed later) Always attempt to estimate one more digit than is displayed by the instrument

28. Instruments come in all sizes and shapes

29. Each one must be read based upon the scale on THAT instrument

30. 10 ml Graduated Cylinder

31. Smallest readable graduation Find two consecutive numbers on the scale Subtract to get difference (40-30=10) Count divisions (#lines plus 1 (9+1=10) Divide difference/divisions to get Smallest Graduation 10/10=1

32. Always attempt to estimate one more reading beyond the display on the instrument Between 52 & 53 52.5 ml is the best reading

33. How to find Uncertainty Factors of Instruments Estimate 1 additional place value beyond the markings Then +/- half of the smallest readable graduation

35. Station A ( Lb/in 2 ) Smallest Graduation? UF?

36. Station B (Volts) Smallest Graduation? UF?

37. Station C (Volts) Smallest Graduation? UF?

38. Station D (Amperes) Smallest Graduation? UF?