Chapter 1 – Science Skills

1. 1.1 – What is Science Chapter 1 – Science Skills

2. What is Science? • A system of knowledge and the methods you use to find that knowledge • Observation and measuring are the means of scientific discovery • The root of science is curiosity!

3. Measurements Qualitative Quantitative Numerical observation Think “QUANTITY” • Descriptive observations • Think “QUALITY”

4. What is technology? • The use of knowledge to solve practical problems • What kind of technology do you use? • What practical problems does that technology solve?

5. Branches of Science • Three Branches of Science • Physical Science • Earth & Space Science • Life Science

6. Scientific Investigations Observations Inferences Something that you think might be true based on observations Evidence-based guesses • Information that is gained through your senses

7. Observations vs. Inferences • Your group will be provided an object. Make three observations and three inferences about this object.

8. 1.2 Using a Scientific Approach The Scientific Method

9. What is the scientific method? • It is a processthat is used to find answersto questions about the world around us.

10. Is there only one scientific method? • No, there are several versions of the scientific method. Some versions have more steps, while others may have only a few. However, they all begin with the identification of a problem or a question to be answered based on observation of the world around us and provide an organized method for conducting and analyzing an experiment.

11. What is a hypothesis? • It is an educatedguessbased on observations and your knowledge of the topic. • ADD TO NOTES • A hypothesis is a proposed answer to a question • A hypothesis is only useful if it is TESTABLE

12. What is data? • It is informationgathered during an experiment. • ADD TO NOTES • Observations • Information that is gained through your senses

13. Steps of the Scientific Method Is the data inaccurate or the experiment flawed? Modify the Experiment

14. Testing a Hypothesis • Experimental Variables • Any factors that can change in an experiment • Two types of Variables • Independent Variable (the manipulated variable) • Dependent Variable (the responding variable)

15. Dancing with the Stars & Variables • Kate Gosselin & Tony Dovolani - Jive • (Start at 3:25)

16. Variables Independent Dependent The variable that is being measured in an experiment This variable changes in response to changes in the independent variable ALWAYS graphed on the X-axis • The variable that is purposefully changed in an experiment by the experimenter • A change in this variable results in a change in another variable • ALWAYS graphed on the Y-axis

17. Example 1 • If a scientist conducts an experiment to test the theory that a vitamin could extend a person’s life-expectancy, then the independent variable is the amount of vitamin that is given to the subjects within the experiment. This is controlled by the experimenting scientist. • The dependent variable, or the variable being affected by the independent variable in this case, is life span.

18. IV & DV Examples Game

19. Controlled Experiments • An experiment in which only one variable, the independent variable, is deliberately changed at a time. • Constants • Experimental variables that must remain consistent in order to test a hypothesis

20. Example 1 • In an experiment designed to test the effect of water temperature on how fast sugar can be dissolved in a pitcher of Kool Aid, what variables should remain constant?

21. Example 2 • In an experiment designed to test which dog food is preferred by dogs, what variables should remain constant?

22. Drawing Conclusions • Conclusions summarize the findings of an experiment • All conclusions should explicitly state whether or not the results of an experiment supported the original hypothesis

23. Scientific Theories • A well-tested explanation for a set of observations or experimental results • Theories are never proved, but rather become stronger if facts continue to support them • Facts are repeatable observations

24. Scientific Laws • A statement that summarizes an observed pattern found in nature without attempting to explain it. • The explanation of such a pattern is provided by a scientific theory

25. 1.3 Measurement Precision & Accuracy

26. Scientific Notation • A way of expressing a value as the product of a number between 1 and 10 and a power of 10 • Makes very large or very small numbers easier to work with • Examples • 300,000,000 can be written as 3.0 x 108 • 0.00086 can be written as 8.6 x 10-4

27. Multiplication & Division • Multiply the numbers before the multiplication signs, then addthe exponents of the 10 • Divide the numbers before the multiplication signs, then subtractthe exponents of the 10

28. Practice • A rectangular parking lot has a length of 1.1 x 103 meters and a width of 2.4 x 103 meters. What is the area of the parking lot? • 4.5 x 103 / 9.0 x 10-1

29. SI Units of Measurement • All measurements must have both a number value and a unit • SI = International System of Units • Units of measurement that are used in scientific investigation • Consists of both base units and derived units

30. SI Base Units

31. SI Derived Units

32. Metric Prefixes • Indicates how many times a unit should be multiplied or divided by 10 • The easiest way to convert from one unit of measurement to another is to use conversion factors • Conversion Factor: A ratio of equivalent measurements that is used to convert a quantity expressed in one unit to another unit

33. SI Prefixes

34. Conversion Factor Example • Mount Everest is 8848 meters high. Convert this number to kilometers. • There are 1000 meters in 1 kilometer • (1000 m/ 1 km)

35. Precision & Accuracy • Precision • A gauge of how exact a measurement is • Accuracy • The closeness of a measurement to the actual value of what is being measured

36. Measuring Temperature • Three types of scales • Fahrenheit • Celsius • Kelvin • You can convert between all three scales using the following formulas • ºC = 5/9 (ºF – 32.0º) • ºF = 9/5(ºC) + 32.0º • K = ºC + 273