1 / 35

Chemistry

Chemistry. T he Science of Matter. Do Now. List at least 5 chemicals that you are familiar with from past experience. Learning Objective. Understand composition and their impact on the properties of matter Be able to classify chemical vs. physical changes. Chemistry.

zita
Download Presentation

Chemistry

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Chemistry The Science of Matter

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

  3. Learning Objective • Understand composition and their impact on the properties of matter • Be able to classify chemical vs. physical changes

  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. Example Two Different Artificial Sweeteners Aspartame Saccharine Different Compositions Both have: C, H, O and N and are sweet Only Saccharine has Na+ and S Their arrangement must be a factor!

  10. 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

  11. What is it made of? • This question is harder to answer • Must take measurements • Must observe chemical changes • Macroscopic Observations • Submicroscopic perspective • To understand hidden structure influences behavior

  12. Physical change vs. Chemical change

  13. Examples

  14. Physical Vs. Chemical Change Worksheet (15 minutes) • In pairs complete the given handout • You may use your notes • Students should each complete an answer sheet as a study guide • Be sure that you are prepared to share your answers with the class

  15. Share Answers

  16. Chemical properties vs. Physical 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 • Physical Property • Transparency: The property of letting light pass through something • 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 • Density: Mass per unit volume

  17. Submicroscopic Level of Matter • Matter is made of Atoms • Atoms • So small they can not be seen with the most powerful light microscope • So small that if a period at the end of a sentence were made of Carbon atoms it would be made of 100 quintillion carbon atoms • (100, 000,000,000,000,000,000) • Counting them at 3 per second would take you a trillion years! • Scanning Tunneling Microscope (STM) • creates computer images which are a visible perspective showing atomic location

  18. Scanning Tunneling Microscope (STM) • individual iron atoms on a silver substrate

  19. Using Chemical Models • Show types and numbers of atoms • Show arrangement of the atoms and space filled

  20. Why Models? • Submicroscopic structural representation • Explains observed behavior • Used to predict behavior not yet observed • Built on investigation and experimentation

  21. Show Connections Between Atoms

  22. 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

  23. 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

  24. Heterogeneous mixture

  25. Heterogeneous mixture

  26. Colloids (look homogeneous but microscopically heterogenous) • Hair spray • Smoke • Cloud • Whipped cream • Shaving cream • Blood • Styrofoam • Gello

  27. Dispersion (Heterogeneous) • Dust • Milk • Hand cream • Gravel • Granite • Sponge

  28. Homogeneous Mixtures

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

  30. 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

  31. 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)

  32. 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)

  33. Answers to pg 7 questions • 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

More Related