1. Classification of Matter

3. Pure Substances  every sample has the same characteristic properties & composition  ELEMENTS  one type of atom Ex: iron (Fe), gold (Au), oxygen (O) (anything off the periodic table)  COMPOUNDS  2 or more types of atoms: Ex: salt (NaCl), sugar (C 6 H 12 O 6 ), water (H 2 O)

4. Mixtures  2 or more substances that aren’t chemically combined and can be separated by physical means  each component keeps its own identity and properties

5. Homogeneous Mixtures  uniform in composition so NO visible parts  also called a solution Ex:  vinegar  air  salt water  brass brass Brass is any alloy of copper and zinc

6. Heterogeneous Mixtures  NOT uniform in composition so you CAN see visible parts Ex:  soil  concrete  blood  chocolate chip cookies  sand in water  soda

7. More Examples of Mixtures

8. Physical Separation Techniques  Filtration- solid part is trapped by filter paper and the liquid part runs through the paper  Vaporization- where the liquid portion is evaporated off to leave solid

9. Physical Separation Techniques  Decanting- when liquid is poured off after solid has settled to bottom  Centrifuge- machine that spins a sample very quickly so that components with different densities will separate

10. Physical Separation Techniques  Paper Chromatography- used to separate mixtures because different parts move quicker on paper than other

11. Practice Determine whether each of the following is element, compound, homogeneous mixture or heterogeneous mixture.  air  zinc  chlorine  granite  aluminum  sugar in water  blood  sucrose  stainless steel  sodium chloride  brass  whole milk  apple  table salt  soft drinks  vinegar  concrete  sodium  baking soda (NaHCO 3 )  gravel