1. Matter is Grainy

2. 2000 B C 1805 1990s Sand on Atomic Tunneling a beach Theory electron microscope

3. Matter Mixtures Pure Substances heterogeneous homogeneous element compound

4. Mixture  Loose combination of materials  Variable composition  Components retain their properties  Can be separated by using differences in properties of components  Heterogeneous or homogeneous

5. Heterogeneous NNon-uniform mixture TTwo or more components or phases clearly visible MMud and water, chunky peanut butter, Italian dressing are examples HHeterogeneous mixtures are called suspensions

6. Homogeneous  Uniform mixture  Appears to contain only one phase or component  saltwater, creamy peanut butter, non- carbonated beverages are examples  Homogeneous mixtures are called solutions

7. Pure Substance  Definite, non-variable composition  Homogeneous  Characteristic set of properties  Elements or Compounds

8. Element  Cannot be broken down chemically into simpler substances  Homogeneous  Characteristic set of properties  Contains only one type of atom

9. Compound  Can be broken down chemically into simpler substances  Homogeneous  Characteristic set of properties which radically differ from the pure elements in it  Contains two or more types of atoms chemically combined  Binary-two elements, tertiary-three elements, quaternary –four elements

10. Alloy  An alloy is a solid solution  A homogeneous mixture of metals  18 carat gold, sterling silver, steel, dental amalgums are all examples  They are usually mixed while molten, then solidified

11. Solution is a homogeneous mixture of  a solute and a solvent  Solute is the dissolvee  Solvent is the dissolver  In aqueous solutions, the solvent is water

12.  To make a mixture, just mix the components together  They keep their characteristic properties  How do you separate a mixture?  Use differences in the properties of the components

13. Separating Mixtures  Distillation- separate solutions  Filtration- separate suspensions  Chromatography- separate solutions  Decanting- separate suspensions

14. Distillation Uses differences in boiling point to separate the components of a solution( non-volatile solute) Heat the solution in a flask Condense the vapor and collect the liquid in a new container Solid solute remains in the boiling flask Used to make distilled water

15. Fractional Distillation Uses differences in boiling point to separate the components of a solution of liquids Heat the solution in a flask Force the vapor up a tall column Higher boiling liquids recondense and don’t reach the condensor Lowest boiling liquid’s vapor gets condensed and collected Then the next lowest boiling liquid can reach the condensor and be collected. This continues until all the liquids have boiled off and been collected Use to refine petroleum into gas, gasoline, kerosene, diesel, etc.

16. Decanting Pour off the liquid from a suspension leaving the solid on the bottom of the container Used in the salt sand separation lab Wine sits in a decanter before it is poured at the table into glasses.

17. Filtration Pour off the liquid from a suspension through a filter in a funnel and collect the liquid in a container Solid stays on the filter paper Sediment free liquid(filtrate) collects in container under funnel

18. Chromatography Put a dot of ink on a long strip of filter paper Hang the paper on a rod on top of a beaker with some water(or other solvent) The bottom of the paper should hang in the water Water travels up the paper and carries the dyes in the ink with it. Lighter (Mass)dyes travel farther up the paper, faster than heavier dyes, and they are separated by mass on the strip Modern gas chromatographs are used in forensics to analyze liquids for different solutes contained in solution

19. Colloid Size of particles in solvent are between those in a suspension and those in a solution As a result, they don’t settle(Mud settles) and are hard to filter(cannot filter solutions) Tyndall Effect- colloidal particles are big enough to scatter light and the beam of light can be tracked through the solution. Solutions don’t reflect light.

20.  To make a compound, a chemical reaction must occur which bonds the atoms of the two elements together  How do we know a reaction has occurred?  Hydrogen gas + oxygen gas are sparked  Flames shoot out of balloon and water vapor is formed  In a chemical change, the product has new properties(unlike the original materials) and a noticeable energy change is observed

21.  In the formation of water, energy is released to the surroundings.  Heat comes out of the reaction- exothermic process  Reactions like these are called exothermic  Do all reactions release energy when they occur?  Some(photosynthesis) use up energy when the react  Heat goes into the reaction- endothermic

22.  In exothermic reactions, the temperature goes up  Burning a log in a fireplace gives off heat to the room, room temperature goes up  In endothermic reactions, energy is taken from the surroundings and stored in products  An endothermic reaction lowers the temperature as it runs

23.  Physical changes also involve energy changes, both endo and exothermic  Melting water requires an input of energy(endo) with no change in temperature of the ice- water mixture, but it is very small by comparison to the chemical change which formed the water  Likewise boiling water requires an input of energy(endo ) with no change in the boiling water’s temperature. It is larger than for melting, but still very small compared to the chemical change.  Freezing water and condensing steam release(exo) exactly the same amount of energy put in to melt and boil them

24.  Roasting can be used to break up compounds of fairly stable elements  Iron, copper, mercury are made in this fashion by roasting ores(oxides) of these metals  Electrolysis is used to break up compounds of unstable elements  Electrolysis is passing an electric current through the material  Water can only be broken up into hydrogen and oxygen by electrolysis

25.  There are four indicators that a chemical change has occurred  Only one of them needs to be present for the change to be chemical  A noticeable energy change  A change in the color  Formation of a precipitate(ppt)  Formation of a gas