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Chemistry

Chemistry. T he Science of Matter Upward Bound Program Summer 2012. What is Chemistry?. It is the study of the composition of matter and the changes that matter undergoes. Do Now. List at least 5 chemicals that you are familiar with from past experience. Chemistry.

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Chemistry

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  1. Chemistry The Science of Matter Upward Bound Program Summer 2012

  2. What is Chemistry? • It is the study of the composition of matter and the changes that matter undergoes.

  3. Do Now • List at least 5 chemicals that you are familiar with from past experience.

  4. Chemistry • The science that investigates the structure and properties of matter • Matter: anything that takes up space and has mass • Mass: the measure of the amount of matter that an object contains • NOT Matter- • Heat • Light • Radio waves etc.

  5. Matter continued • Structure: refers to what it is made of and of how it is organized • Properties: Describe the characteristics and behavior of matter including the changes it undergoes

  6. Behavior of Matter • Determined by BOTH • The elements it contains • Arrangement of those elements

  7. Example Salt vs. Water Sodium and Chloride Hydrogen and Oxygen Contain different elements --- Have different properties!

  8. Example • Aspirin Vs Table Sugar • Both contain only Carbon, Hydrogen and Oxygen molecules --- same composition • Different Structures Cause Different Behaviors!

  9. Identifying Properties • Many are easy to observe by simple tests • Use heat, magnets, electricity etc • Color • State: solid, liquid or gas at room temp and pressure • Soft or hard • Does it burn? • Does it dissolve in water? • These are from a macroscopic perspective • Things you can touch, taste, feel, smell and see

  10. Physical change vs. Chemical change

  11. Examples

  12. Physical Vs. Chemical Change Worksheet (10-15 minutes) • In groups complete the given handout • You may use your notes • Be sure that you are prepared to share your answers with the class

  13. Share Answers (3 min/group) • Be sure to explain why you chose your answer. • Each table shares their answers with the class. • ALL STUDENTS MUST RECORD THE CORRECT ANSWER ON THEIR HANDOUT!

  14. Homework

  15. Classifying Matter • Substance: matter with constant composition • Element: Made of only one type of atom • Compound: 2 or more elements that are chemically combined • Mixture: Matter with variable composition • Heterogeneous Mixture: Made up of more than 1 phase • Homogeneous Mixture: also called solutions, made up of only 1 phase

  16. Mixtures • A material that is made of 2 or more things which are not combined chemically • Each of the parts still keep their own identities • Made by blending, but NOT forming chemical bonds or chemical change! • Most everyday matter occurs as mixtures

  17. Heterogeneous and Homogeneous Mixtures • A classification of matter based on composition • Homogeneous mixture: no clumping or grouping but rather a uniform dispersal of the material it is made of. • Ex. Air; made of N2, O2, CO2 and other gases • A liquid in which there is a solvent and a solute is called a solution • Heterogeneous mixture: it is easy to identify all if the different components

  18. Homogeneous Mixtures

  19. REMEMBER Mixtures • Are made of 2 or more things which are not combined chemically • Each of the parts still keep their own identities • Made by blending, but NOT forming chemical bonds or chemical change! • Most everyday matter occurs as mixtures

  20. Separating Mixtures • Mixtures can be separated through a physical process, (the identity of the substance remains unchanged). • Using their Physical properties • Bringing about physical changes to separate the mixture into its components (different substances it is made of)

  21. Making a Mixture AND SAND SUGAR

  22. The Mixture

  23. How can we separate it? • What do you think? • Work with your lab partner to come up with a suggested method. (10 minutes) • You may use your class notes, but your brain is your best asset. • Write your thoughts in your notebooks. • Do not be afraid to try!

  24. Report out on ideas • So, what did you come up with? • Share your thoughts! (10 minutes)

  25. What can we do? Method #1 Use a pair of tweezers and a microscope to physically separate the particles Requires a lot of time and patience

  26. Method #2 Step #1 Recall the properties of water and of sand Sugar dissolves in water Sand does NOT Use the difference!

  27. Step #2 Recall the properties again sand will not pass through a filter Sugar and water solution will Use the difference!

  28. Step #3 Recall the properties of sugar and water sugar will not evaporate (change state) at 100 degrees Celsius water will ! Use the difference! Step #4

  29. You have the two pure substances again! • Sand in the filter! • Sugar in the bottom of the beaker!

  30. Lab Tomorrow • Separating Mixtures

  31. REMEMBER: Physical Properties • Density: Mass per unit volume • Solubility in water : Does it dissolve in water? • State of mater: at room temp and pressure • Transparency: lets light pass through • Boiling point: Temperature at which a substance goes from liquid to gas • Melting point: Temperature at which a substance goes from solid to a liquid • Brittleness: Tendency to crack or break • Ductility: Ability to bend without breaking • Elasticity: Ability to be stretched or compressed then return to original size

  32. Chemical properties • Chemical Property • Flammability: The ability to burn • Ability to rust:Reacts with oxygen to produce rust • Reactivity with vinegar: Reacts with vinegar to produce new substances

  33. Solutions (homogeneous) • Air (gas) • Martini (liquid) • Salt water (liquid) • Plastic (solid)

  34. Substances • Homogeneous materials that contain only 1 kind of matter • Have definite composition and properties • Substances which can not be broken down into a simpler substance is an ELEMENT. • Substances which can be broken down into a simpler substance is a COMPOUND. • They are made of 2 or more elements

  35. Elements • Made of only one kind of atom • Can not be made simplified by physical or chemical means • Can exist as atoms (carbon) or molecules (N2)

  36. Compounds • Consist of 2 or more DIFFERENT atoms bound together (H2O) • Can be broken down into smaller types of matter by chemical means only. • Have properties which are different than the elements they are made of • Always contain the same ratio of its components atoms ( ex 2 hydrogen's to 1 oxygen, in water)

  37. Elements, Compounds, Mixtures • Sodium is an element. • Chlorine is an element. • When sodium and chlorine bond they make the compound sodium chloride, commonly known as table salt. Compounds have different properties than the elements that make them up. Table salt has different properties than sodium, an explosive metal, and chlorine, a poisonous gas.

  38. Classify the Following • Ocean water- • Calcium- • Vitamin C- • Dry ice – • Copper- • Grain alcohol- • after shave lotion- • Hamburger- • Al foil – • Milk- • Salt- • Iron nail-

  39. Answers • Ocean water- solution • Calcium- element • Vitamin C- Compound ( L-asorbic acid) • Dry ice – compound (CO2) • Copper- element • Grain alcohol- compound (C2H5OH) • after shave lotion- heterogenous mixture • Hamburger- hetero • Al foil – element • Milk- solution • Salt- cmpd • Iron nail- element

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