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Chemistry??

Chemistry??. What is that? And why do I need to study it? Unit 1 = Ch. 2 pg. 29-61. Part 1: What is Chemistry? . Study of matter and changes that matter undergoes What is matter? Anything that has mass and takes up space (stuff things are made of). Importance of Chemistry.

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Chemistry??

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  1. Chemistry?? What is that? And why do I need to study it? Unit 1 = Ch. 2 pg. 29-61

  2. Part 1:What is Chemistry? • Study of matter and changes that matter undergoes • What is matter? • Anything that has mass and takes up space (stuff things are made of)

  3. Importance of Chemistry • Chemistry is all around us. • Clothes you wear = made of synthetic fibers or natural fibers that have been dyed • Air you breathe • Food you eat (Ex = baking powder reacts with acid in batter to make carbon dioxide to make a fluffy cake) • Beauty products = nail polish remover, hair spray, deodorant • Gas for you car = petroleum product • Computers you use = silicon memory chips • Agriculture = insecticides, herbicides, fungicides • Chemistry is often said to be the central science

  4. How do I experiment with science? • The Scientific Method • A logical approach to the solution of scientific problems • Uses common sense to solve problems

  5. Scientific Method • EXAMPLE: Susan read that certain perfume smells would agitate bees since they contained chemical X. Because perfume chemical formulas are secret, she decided to determine whether the unknown chemical X was present in two different perfumes by observing the bees’ behavior. First, she placed a saucer of water 3 feet from the hive. She recorded the time required for the bees to emerge. Then she placed a saucer containing the first perfume 3 feet from the hive and recorded again. After a 30 minute recovery period, she tested the second perfume. All experiments were conducted on the same day when the wind and temperature were similar.

  6. Scientific Method The Steps of the Scientific Method: • Make observations & form a testable question • What question are you trying to answer? Does chemical X agitate bees? • Do research • What do you already know about the problem that will help you form a testable hypothesis? • This is your background information from textbook, teacher, online sources, etc. • Cite sources!

  7. Scientific Method • Citing Sources • “Name of article.” Web Page. 15 August 2013. www.entirewebaddress.com. • “ScienceGeek.net Homepage.” 15 August 2013. www.sciencegeek.net.

  8. Scientific Method • Hypothesis • A testable statement/prediction • Written as “If….Then” statement • "If _____[I do this] _____, then _____[this]_____ will happen.” IF chemical X agitates bees and different perfumes are tested, THEN bees will emerge fastest if the perfume contains chemical X. • Procedure • Numbered steps you take to conduct the experiment • BE DETAILED! • Another person should be able to EXACTLY repeat your experiment using your procedure

  9. Scientific Method • Hypothesis Practice: • Bill wanted to see what effect food color had on the amount of food fish ate. • What hypothesis could you write for this experiment? • Remember: “IF…THEN” • If fish are fed bright colored food, then they will eat twice as much food.

  10. Scientific Method • Parts of an Experiment • Independent Variable – what you change or test Different perfumes • Dependent Variable – what is measured as a result of the independent variable (what happens or what you look for) Time it takes for bees to emerge • Constants – what you keep the same Same day, same wind, same temperature, same beehive, same bowl • Control Group – what is measured against or compared to (the normal) Bowl with water only • Multiple Trials – makes experiment more valid with more data to average

  11. Scientific Method • Results • What you record or observe while performing the experiment in table and/or graph • Data should be empirical (THE NUMBERS) with no discussion or comment • Include all calculations made during the experiment • Conclusion • Did the results support or not support your hypothesis? • EXPLAIN why using your data • List one thing you learned and describe how it applies to a real-life situation • Discuss possible errors that could have occurred

  12. Scientific Method Hypothesis is Supported Hypothesis is NOT Supported

  13. Scientific Method • Method Practice: • Scientists observed that white mice that were fed seeds appeared to grow more than mice given leafy greens and yellow vegetables. The scientists hypothesized that the protein in the seeds was responsible for the growth. They experimented with 200 mice of the same age, size, health and gender by dividing them into 2 groups. One group was given a diet of normal protein of vegetables. The other group was given a diet high in protein of seeds. The mass of each mouse was recorded daily for 30 days. The average mass increase for the normal diet group was 8 grams. The average mass increase for the seed group was 17 grams. • What is the independent variable? Mice diet • What is the dependent variable? Mass of the mice • What is the control group? Mice with normal diet • What should the conclusion be? The added protein in the seed diet increased the mass of the mice by an average mass of 9 grams.

  14. Scientific Method • COMPLETE SCIENTIFIC METHOD WORKSHEET. • BE PREPARED FOR SCIENTIFIC METHOD QUIZ NEXT CLASS PERIOD.

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