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August 30-31 WarmUp: Agenda and complete egg in a bottle lab report

Chemistry WarmUp Copy ALL of these assignments into your binder Including dates, WarmUps, InClass assignments AND page numbers!. August 30-31 WarmUp: Agenda and complete egg in a bottle lab report InClass: Safety Contract review InClass: Lab Bubbles p23

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August 30-31 WarmUp: Agenda and complete egg in a bottle lab report

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  1. Chemistry WarmUp Copy ALL of these assignments into your binderIncluding dates, WarmUps, InClass assignments AND page numbers! August 30-31 WarmUp: Agenda and complete egg in a bottle lab report InClass: Safety Contract review InClass: Lab Bubbles p23 Homework: Read and take notes 1.3 p25 q18-25DUE NEXT CLASS Setpember 1 WarmUp: Hypothesis/Procedure/Observations InClass: Introduction to Dimensional Analysis Homework: Read 1.4 answer q26-27p30 DUE NEXT CLASS September 2-3 WarmUp: Scientific Method and the Bubbles Lab Revisited InClass: An Experimental Approach to Science p21TE InClass: Self-assess bubbles lab Quiz: Scientific Method ch1.1-1.3 Lab: Using the metric system Homework: Read 2.1 answer q3-7 DUE NEXT CLASS As soon as you finish copying these assignments: Carefully read over and complete your Egg in a Bottle lab report. Compare your use the rubric to assign yourself a grade.

  2. Announcements SLAC: LEADING THE CHARGE: Exotic New Materials for Future Devices September 28th 7:30-8:30 For extra credit (10 homework or inclass points) turn in •Program •Your notes signed by the presenter or organizer. http://www2.slac.stanford.edu/lectures/ EYH: October 9, 2010 UCSC http://eyh.ucsc.edu/

  3. Chapter 1 Introduction to Chemistry

  4. Chapter 1 Introduction to Chemistry

  5. What is Chemistry? • Study of matter composition, properties, & changes • Applied chemistry attain goals • Pure chemistry gather knowledge for knowledge’s sake

  6. Why study Chemistry • Explain the natural world • Why? • Prepare for a career • Directly- in a lab • Indirectly- problem solving and thinking skills • Be an informed citizen • Vote • Don’t get scammed

  7. 1.3 Alchemy • Forerunner of chemistry • Mystical- search for perfection • Practical- developed glassware and techniques used today • Tried to change elements • Faulty assumptions and lack of logic led them astray

  8. Scientific Method • A way of solving problems or answering questions. • Starts with observation- noting and recording facts • Hypothesis- possible explanation of a set of observation • based on research • and previous knowledge

  9. Scientific Method • Experiment- designed to test the hypothesis • only two possible answers • hypothesis is right • hypothesis is wrong • Generates data -observations from experiments. • Modify hypothesis - repeat the cycle

  10. Scientific Method

  11. Scientific Method

  12. Variables • Controlled experiment- one thing is changed. • Manipulated variable- What you change or control directly • Also called independent variable • Responding variable – What changes as a result. No direct control • Also called dependent variable

  13. Origin of Life 13

  14. Aristotle (384 –322 BC) Proposed theory of spontaneous generation Also called abiogenesis Living things can arise from nonliving matter Idea lasted almost 2000 years 14

  15. 15

  16. Examples of Spontaneous Generation 16

  17. Example #1 Observation:Every year in the spring, the Nile River flooded areas of Egypt along the river, leaving behind nutrient-rich mud that enabled the people to grow that year’s crop of food. However, along with the muddy soil, large numbers of frogs appeared that weren’t around in drier times 17

  18. Example #1 Conclusion: It was perfectly obvious to people back then that muddy soil gave rise to the frogs 18

  19. Example #2 Observation:In many parts of Europe, medieval farmers stored grain in barns with thatched roofs (like Shakespeare’s house). As a roof aged, it was not uncommon for it to start leaking. This could lead to spoiled or moldy grain, and of course there were lots of mice around. 19

  20. Example #2 Conclusion:It was obvious to them that the mice came from the moldy grain. 20

  21. Example #3 Observation:Since there were no refrigerators, the mandatory, daily trip to the butcher shop, especially in summer, meant battling the flies around the carcasses. Typically, carcasses were “hung by their heels,” and customers selected which chunk the butcher would carve off for them. 21

  22. Example #3 Conclusion:Obviously, the rotting meat that had been hanging in the sun all day was the source of the flies. 22

  23. Abiogenesis Recipes Recipe for mice: Place a dirty shirt or some rags in an open pot or barrel containing a few grains of wheat or some wheat bran, and in 21 days, mice will appear. There will be adult males and females present, and they will be capable of mating and reproducing more mice. 23

  24. Disproving Spontaneous Generation 24

  25. Francesco Redi 25

  26. Step 1 - Observation There were flies around meat carcasses at the Butcher shop. Where do the flies come from? Does rotting meat turn into or produce rotting flies? 26

  27. Step 2 - Hypothesis Rotten meat does not turn into flies. Only flies can make more flies. 27

  28. Redi’s (1626-1697) Experiments What is the the manipulated variable? 28

  29. Redi’s (1626-1697) Experiments What is the the manipulated variable? 29

  30. Redi’s (1626-1697) Experiments Name several controlled variables: What is the responding (dependent) variable? 1. Unsealed – maggots on meat 2. Sealed – no maggots on meat 3. Gauze – few maggots on gauze, none on meat 30

  31. Disproving Spontaneous Generation of Microbes 31

  32. Observations • Cycle repeats many times. • By you and by others • The hypothesis gets more and more certain. • Becomes a theory • A thoroughly tested model that explains why things behave a certain way. Hypothesis Experiment

  33. Observations • Theory can never be proven. • The best explanation • Useful because it predicts behavior • Helps us form mental pictures of processes (models) Hypothesis Experiment

  34. Observations • Another outcome is that certain behavior is repeated many times • Scientific Law is developed • Description of how things behave • Usually an equation • Law - how • Theory- why Hypothesis Experiment

  35. Theory (Model) Modify Prediction Experiment Law Observations Hypothesis Experiment

  36. Communication • Use Journals • Do research • Write article • Describe procedures, methods, and findings • Submit for peer review • Sent back for editing • Publish • Letters to editor respond.

  37. Collaboration • Working together • Teams • Different skills • Different specialties • Internet and Email • Conferences

  38. Chemistry Warm Up 1. How does a hypothesis become a theory? 2. Are theories ever wrong? 3. If a scientist subscribes to a hypothesis, but performs an experiment that disproves the hypothesis what should he or she do? 4. Explain the role of collaboration and communication in the scientific method. 5. What is a. manipulated variable? b. responding variable? c. controlled variable? Grading for this warm up: I didn’t understand, so I put my name and the date on the paper, and wrote down the questions – 1 point I wrote complete and correct answers to at least half of the questions – 2 more points (total of 3 points) I wrote complete and correct answers to all of the questions 2 more points (total of 5 points) When you finish, read and take notes 1.4 and andswer 26 and 27 in that chapter.

  39. Problem Solving • Only way to get good is to practice • Two parts • Developing Plan- • Hard part • Higher level thinking • Implementing Plan- • Not so hard • Application level

  40. Solving Numeric Problems • Three steps- • Analyze • Known • Numbers • Measurements • Equations • Unknown • What are you looking for? • What units?

  41. Solving Numeric Problems • Three steps- • Analyze • Plan • The heart of problem solving • Diagram • Look info • Table • Graph • Equation

  42. Solving Numeric Problems • Three steps- • Analyze • Calculate • Easiest part • Convert measurements • Rearrange • Appendix C

  43. Solving Numeric Problems • Three steps- • Analyze • Calculate • Evaluate • Reasonable? • Read the question, did you answer it? • Check your work • Estimate

  44. Practice • What is the length, in centimeters, of a 10.0-inch ruler, given that there are 2.54 centimeters per inch?

  45. Practice • A certain ball when dropped from any height, bounces one-half the original height. If the ball was dropped from a height of 60 in. and allowed to bounce freely, what is the total distance the ball has traveled when it hits the ground for the third time? Assume the ball bounces straight up and down.

  46. Conceptual Problems • Without numbers or math • Two steps • Analyze • Identify known and unknown • Plan • Solve

  47. Practice • You find a sealed box with strings protruding from three holes, as shown in the diagram. When you tug string A, it becomes longer and string C becomes shorter. When you tug string B, it becomes longer, but strings A and C are not affected. Make a diagram showing the arrangement of the strings inside the box.

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