The Scientific MethodSignificant Figures<br />
The Scientific Method<br /><ul><li>Based on Observations and Data
Observations – hopefully quantitative measurements that appear to relate two or more concepts:  heating time and temperatu...
Law – Statement or equation showing the relationship between properties or concepts
Hypothesis – a proposal to explain the relationship between one concept or property on another
Experiment – set of controlled steps that are meant to determine whether or not the hypothesis is correct.  Control for ot...
More Experiments/Evaluation of Hypothesis – Further tests to see if predicted behavior holds
Theory – Hypothesis that has held up after many experiments and tests</li></li></ul><li>The Scientific Method<br /><ul><li...
An hypothesis is often changed as new kinds of data or methods of measurement become available.
Once tested, an hypothesis becomes a Theory.  Theories are used to explain the behavior of things until different or bette...
Scientific Laws provide a relationship (usually mathematical) that is widely used and accepted, but do not usually provide...
Accuracy vs Precision<br />
Significant Figures<br /><ul><li>Used to indicate the degree to which a number is “known”
If you weigh 150 pounds, does that mean you weigh 150 + 0.1 , 150 + 1, or 150 + 10?
Since 1 kg = 2.205 lb, how many kg do you weigh?  </li></ul>150 lb x (1 kg/2.205 lb) = 68.0272 kg<br /><ul><li>If you are ...
Determining Significant Figures<br />
Rules for Using Significant Figures<br />
Rules for Using Significant Figures<br />
Using Significant Figures<br />
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Chapter1

  1. 1. The Scientific MethodSignificant Figures<br />
  2. 2. The Scientific Method<br /><ul><li>Based on Observations and Data
  3. 3. Observations – hopefully quantitative measurements that appear to relate two or more concepts: heating time and temperature, pond depth and sound of splash, number of “skips” compared to “flatness” of rock, etc.
  4. 4. Law – Statement or equation showing the relationship between properties or concepts
  5. 5. Hypothesis – a proposal to explain the relationship between one concept or property on another
  6. 6. Experiment – set of controlled steps that are meant to determine whether or not the hypothesis is correct. Control for other variables is important
  7. 7. More Experiments/Evaluation of Hypothesis – Further tests to see if predicted behavior holds
  8. 8. Theory – Hypothesis that has held up after many experiments and tests</li></li></ul><li>The Scientific Method<br /><ul><li>The experiment must control for the variables that might impact the observations beside the one(s) you are trying to test.
  9. 9. An hypothesis is often changed as new kinds of data or methods of measurement become available.
  10. 10. Once tested, an hypothesis becomes a Theory. Theories are used to explain the behavior of things until different or better ways of making observations become available, and remain valid unless the new observations provide conflicting predictions. </li></li></ul><li>Scientific Law<br /><ul><li>Scientific Laws, like the Law of Gravity or Newton’s Laws of Motion, are rare.
  11. 11. Scientific Laws provide a relationship (usually mathematical) that is widely used and accepted, but do not usually provide an explanation of the observed effect. </li></li></ul><li>Accuracy vs Precision<br />Accurate and Precise<br />Precise<br />Systematic error<br />Accurate<br />Neither Accurate nor Precise<br />Random Error<br />
  12. 12. Accuracy vs Precision<br />
  13. 13. Significant Figures<br /><ul><li>Used to indicate the degree to which a number is “known”
  14. 14. If you weigh 150 pounds, does that mean you weigh 150 + 0.1 , 150 + 1, or 150 + 10?
  15. 15. Since 1 kg = 2.205 lb, how many kg do you weigh? </li></ul>150 lb x (1 kg/2.205 lb) = 68.0272 kg<br /><ul><li>If you are 5 ft, 8 in tall, what is your average density? </li></li></ul><li>
  16. 16.
  17. 17. Determining Significant Figures<br />
  18. 18. Rules for Using Significant Figures<br />
  19. 19. Rules for Using Significant Figures<br />
  20. 20. Using Significant Figures<br />
  21. 21. Chemical Conversions<br /><ul><li>Unit conversions and dimensional analysis are very important parts of calculations in chemistry.
  22. 22. A conversion factor is an equation that relates two different units to one another. </li></ul>Simple: 100 cm = 1 m<br />More difficult: 1 in = 2.54 cm<br />
  23. 23. Simple conversion<br />
  24. 24. SI Base Units<br />
  25. 25. Decimal Conversions<br />
  26. 26. English to SI Conversions<br />
  27. 27. Temperature Conversion<br />Celsius/Fahrenheit Conversion<br />Relation between degrees: 1 oC = 1.8 oF<br />T(oF) = 1.8 x T(oC) + 32<br />Celsius/Kelvin Conversion<br />Relation between degrees: 1 oC = 1 K<br />T(K) = T(oC) + 273.15<br />
  28. 28. Problems<br />1.15, 1.19, 1.22, 1.43, 1.49, 1.51, 1.53, 1.57, 1.60, 1.62, 1.67, 1.70, 1.72, 1.74, 1.75, 1.87<br />

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