Module

1. Module

2. Module 1 What is Science? Scientia = knowledge “Process that uses observations and investigations to gain information about events in nature.”

3. Module 1 What is the scientific method? – organized set of investigating procedures State the problem Gather information Form a hypothesis Test hypothesis Analyze data Draw conclusions

4. This could be a question about an observed problem or curiosity. It is never wrong to have a wrong hypothesis. Your conclusions should simply either support or not support you hypothesis. Researching aspects of the problem to understand it. A possible explanation for a problem – this may be right or it may be wrong. Develop an experiment to try to prove or disprove your hypothesis. The data will either support or not support your hypothesis. The data speaks for itself and should be viewed without prejudice The conclusion should refer to the data as either the validation of or the contradiction to your hypothesis.

5. Module 1 Variables are quantities or values which can have more than one number. What are variables? What are the two kinds of variables? Dependent variables – This is the responding variable – the variable that is measured by the experimenter Independent variable – This is the manipulated variable – the variable which is controlled and changed by the experimenter. The expression DRY MIX can help you remember and understand the difference between the two.

6. Module 1 D R Y M I X D D R R -- Y Axis Y -- Dependent Variable -- Responding Variable (measured) M M -- Manipulated variable (controlled) I I -- X - Axis X X -- Independent Variable (controlled)

7. Module 1 What are Constants in an experiment? A Constant or Constant Variable is a variable which does not change during the course of the experiment Example: During an experiment which measures the effect of temperature on plant growth, the constants might be soil type, plant type, amount of sunlight, amount of water. All variables in an experiment should be held constant except the experimental variables (dependent and independent)

8. Module 1 What is a control in an experiment? A control is a standard for comparison in an experiment. For example, in an experiment which measures the effect of temperature on plant growth, a plant at room temperature is used to compare other plants at various temperatures. The control is the basis for comparison of changes which take place in the dependent (responding) variables.

9. Module 1 What is an observation? In science an observation is information collected by the senses – all of the sense – not just visual. That information is often called data. There are two types of data: Qualitative data is information that is descriptive which does not involve measurements. Quantitative data are observations in the form of measurements.

10. Module 1 What are models and how are they used in science? A model is something which represents a concept which is either very small (the atom), very large (the solar system), or difficult to access the real thing (an eyeball). Models help students to better understand concepts and relationships.

11. Module 1 What is the difference between a hypothesis, theory, and law? A hypothesis is a possible answer to science question? Hypotheses may be right or wrong – they give the experimenter a basis to prove or disprove. A theory is an explanation of a thing or event based on knowledge gained from experiments or investigations.

12. Module 1 A scientific law is a rule of nature which seems to be always true. The law of gravity

13. Module 1 What is a measurement standard? A measurement standard is an agreed-upon exact quantity for measuring. What is a unit? A unit is measurement quantity used to describe a measurement value. UNITS ARE IMPORTANT. A measurement contains a number and a unit. The number is the adjective and the unit is the noun. The number describes (modifies) the unit.

14. Module 1 Example – This morning I awakened early and ran five before breakfast. Five what ? 5 miles, 5 minutes, 5 meters, 5 secs, 5 feet. Numbers in a measurement are MEANINGLESS without units.

15. Module 1 The Metric System – Base units & SI Prefixes And all of these prefixes You must know these

16. Module 1 Length SI unit of length is the meter Definition - distance light travels in a vacuum in 1/299,792,458 of a second. A meter is about the distance from the floor to a doorknob. Measurements smaller than a meter are usually centimeters. Longer distances are usually in kilometers.

17. Module 1 Mass - amount of matter in an object SI Unit is the kilogram. Standard is a palladium-iridium cylinder kept in France. One liter of water has a mass of 1 kilogram. A paper clip has a mass of about a gram. Smaller mass quantities are measured in milligrams.

18. Module 1 Time - Second 1/60th of a minute Also defined by the number of vibrations of a Cesium-133 atom.

19. Units of Temperature – Temperature simply measures how hot or cold something is In science temperature is measured in degrees Celsius (oC). In daily life temperature is measured in degrees Fahrenheit (oF). (For example, The high temperature for today is 82 oF or body temperature is 98.6 oF) Converting between oF and oC: oC = 5/9(oF – 32) oF = 9/5oC + 32 Practice: 98.6oF = ___ oC oC = 5/9 (98.6 – 32) = 37oC

20. Temperature conversions practice: Convert -12oC to oF oF = 9/5 (-12) + 32 = 10.4 oF Kelvin Temperature Scale – A third temperature scale used to perform temperature calculations. oC and oF temperatures do not show proportional relationships and are rarely used in calculations because they have zero and negative values. Kelvin is related to oC in the following way: K = oC + 273 Practice: 200oC = ____K 73

21. Derived Units - units which get their meaning from other units Volume - amount of space an object occupies. Volume is derived from units of length. 1 Liter is equal to 1 dm3 or 1000 cm3 10 cm 10 cm 1 dm = 10 cm 10 cm

22. Module 1 Density - A Derived Unit Density is derived from units of mass and volume and refers to the overall “lightness” or “heaviness” of a substance. m v mass volume or d = Density = The density of water is 1.00 grams/cm3 . Objects with a density less than 1 gram/cm3 will generally float in water and objects with a density greater than 1.00 grams/cm3 will generally sink in water.

23. Module 1 Units of Measurement in Calculations. Conversion Factors Definition - a problem-solving method based upon treating units in calculations as if they are algebraic factors. • Unit Conversions (or conversion factors) are • a fraction with units • equal to a value of ONE

24. Module 1 Using a Conversion Factor How many hours are in 1 Week? hours What is your unknown? What is your known? 1 Week Find numerical relationships which link your known to your unknown. 1 wk = 7 days 1 day = 24 hours

25. Module 1 Solving Problems Start with your known 7 Days 1 Week 24 hours 1 day ------ 1 Week X X = 168 hrs ------- ------- ---- Multiply by conversion factors which cancel the unit Cancel the units, leaving the units to the unknown. Solve the problem.

26. Module 1 What are Significant Figures? Definition - The number of digits in a measurement known to be exact, plus the last digit which is estimated. This will show you why 5 X 5  25 Significant Figures relates directly to accuracy.

27. Significant Figures Rules • Nonzero Digitsaresignificant. 677.3 mm = 4SF • All zeros between nonzero digitsaresignificant. 7.003 grams = 4SF • Zeros which begin a number containing a decimalare NOTsignificant. 0.00045 mL = 2SF • All zeros which end a number containing a decimal pointaresignificant. 1.00 meters = 3SF • Zeros ending a number with no decimal point are questionable and are assumedinsignificant. 40,000 people = 1SF

28. Module 1 Practice Problems 7.70 grams 3sf 0.0050 meters 2sf 612,000 microbes 3sf 5.000 km 4sf 50070 mm 4sf 6.020 X 1012 atoms 4sf

29. Module 1 Calculations involving Sig Figs Addition and Subtraction When adding or subtracting measurements, the final answer may have no more digits to the right of the decimal point than the measurement with the fewer number of digits to the right of the decimal point.

30. Addition and Subtraction Examples 4.12 grams + 4.2 grams 2 digits to the right of decimal 1 digit to the right of decimal / 8.32 grams Answer limited to 1 digit to the right of the decimal 8.3 grams Correct answer 53.787 meters - 7.32 meters 3 digits to the right of decimal 2 digits to the right of decimal / 46.467 meters Answer limited to two digits to the right of the decimal Since the number rounded off is 5 or greater the last digit is rounded up one. Answer 46.47 meters

31. Multiplication and Division The answer to a multiplication or division problem may have no more significant figures than the measurement with the fewer (or fewest) number of significant figures. CALCULATOR GIVES THE WRONG ANSWER!! / / 33.67 mm x 6.26 mm = 210.7742 mm 2 / / Calculator gives answer with 7 sf 3sf 4sf Round answer off to three sf. Correct answer 211 mm2 Remember that an answer may be no more accurate than the least accurate measurement.

32. Calculations involving Significant Figures 5 m X 5m = 25 m2 / NOT Major Concept: An answer to a calculation may be no more accurate that the least accurate measurement 5 m X 5m = 25 m2 1sf 1sf 2sf

33. Accurate Measurements are important 5.0 m X 5.0 m = 25 m2 Honest, accurate calculation More accurate measurements

34. Density Calculations What is the density of a metal with a mass of 43.6 grams and a volume of 3.77 cm3? 3 sig figs Density = 3 sig figs Calculator answer is 11.56498674 g/cm3 WRONG ANSWER Answer should only have 3 sig figs Correct rounded answer = 11.6 g/cm3

35. Scientific Notation • One number with two parts, used for three reasons: • To represent very large numbers • To represent very small numbers • To clarify accuracy First part of the number is the coefficient 6.023 X 1023 One number with two parts The second part is the base ten exponent.

36. Module 1 A graph is a visual display of data or information. In science data is collected and displayed in a manner to be easily understood and interpreted. This is a bargraph

37. Module 1 This is a pie graph or circle graph. It is used to show parts of a whole. The sum of all parts is equal to 100%

38. Module 1 This is a line graph. It shows relationships between two variables. In this example the variables are temperature and time. Temperature is the dependent variable and time is the independent variable. time (min)

39. Practice Questions • The next series of slides will give you some practice questions to prepare you for the end of course test. • Answers are provided after each question slide. Make sure you think about these carefully. • Please email with questions regarding any questions you do not understand.

40. A regional manager is concerned about the number of employee accidents occurring at his ten service centers. She makes a hypothesis that safety advertising will reduce accidents. She decides to test the hypothesis in her service centers. Each service center will use different number of safety posters to see if the number of accidents will reduce. Each service center manager will keep a record of the employee accidents reported. • How is safety advertising measured in this study? • number of employee accidents reported to the service center manager • number of service centers involved • number of safety posters in each service center • number of accidents in the service center

41. A regional manager is concerned about the number of employee accidents occurring at his ten service centers. She makes a hypothesis that safety advertising will reduce accidents. She decides to test the hypothesis in her service centers. Each service center will use different number of safety posters to see if the number of accidents will reduce. Each service center manager will keep a record of the employee accidents reported. • How is safety advertising measured in this study? • number of employee accidents reported to the service center manager • number of service centers involved • number of safety posters in each service center • number of accidents in the service center

42. A regional manager is concerned about the number of employee accidents occurring at his ten service centers. She makes a hypothesis that safety advertising will reduce accidents. She decides to test the hypothesis in her service centers. Each service center will use different number of safety posters to see if the number of accidents will reduce. Each service center manager will keep a record of the employee accidents reported. How are the employee accidents measured in this study? a. number of employee accidents reported to the service center manager b. number of service centers involved c. number of safety posters in each service center d. number of accidents in each service center

43. A regional manager is concerned about the number of employee accidents occurring at his ten service centers. She makes a hypothesis that safety advertising will reduce accidents. She decides to test the hypothesis in her service centers. Each service center will use different number of safety posters to see if the number of accidents will reduce. Each service center manager will keep a record of the employee accidents reported. How are the employee accidents measured in this study? a. number of employee accidents reported to the service center manager b. number of service centers involved c. number of safety posters in each service center d. number of accidents in each service center

44. Jasmine has been launching water rockets. She can vary the amount of water in the rocket and the launching angle of the rocket. She can also change the weight of the rocket by adding sand to the nose cone. She is curious about the factors which affect of the height to which the rocket will rise. Which of the following is a hypothesis she could test? a. Rockets using warm water will rise higher than rockets with cold water. b. Rockets using five tail fins will rise higher than rockets with four tail fins. c. Rockets with a pointed nose cone will rise higher than rockets with a rounded nose cone. d. Rockets using more water will rise higher than rockets with less water.

45. Jasmine has been launching water rockets. She can vary the amount of water in the rocket and the launching angle of the rocket. She can also change the weight of the rocket by adding sand to the nose cone. She is curious about the factors which affect of the height to which the rocket will rise. Which of the following is a hypothesis she could test? a. Rockets using warm water will rise higher than rockets with cold water. b. Rockets using five tail fins will rise higher than rockets with four tail fins. c. Rockets with a pointed nose cone will rise higher than rockets with a rounded nose cone. d. Rockets using more water will rise higher than rockets with less water.

46. The monthly heating bill for the Smiths is higher than all their neighbors. They formulate hypotheses about factors that affect their heating bill. Which of the following statements is NOT a hypothesis which they could test? a. The greater the number of trees around the house, the lower the heating bill. b. The fewer number of doors and windows in a house the lower the heating bill. c. The larger the house the larger the heating bill. d. The higher the heating bill, the more likely a family will seek cheaper heating methods.

47. The monthly heating bill for the Smiths is higher than all their neighbors. They formulate hypotheses about factors that affect their heating bill. Which of the following statements is NOT a hypothesis which they could test? a. The greater the number of trees around the house, the lower the heating bill. b. The fewer number of doors and windows in a house the lower the heating bill. c. The larger the house the larger the heating bill. d. The higher the heating bill, the more likely a family will seek cheaper heating methods.

48. A high school environmental science class studies factors that might affect pollution in the Reedy River. They discover that possible factors may include fertilizers, sewage, and trash from a landfill. Chemicals in that portion of the river are not a problem because there are no chemical plants upstream. Which of the following is a testable hypothesis? a. The more fertilizer in the river, the more crops will grow along the river. b. The more chemical plants there are, the more chemical pollution that results. c. The more trash sent to the landfill, the higher the income of families in the region. d. The more sewage in the river, the greater the level of pollution.

49. A high school environmental science class studies factors that might affect pollution in the Reedy River. They discover that possible factors may include fertilizers, sewage, and trash from a landfill. Chemicals in that portion of the river are not a problem because there are no chemical plants upstream. Which of the following is a testable hypothesis? a. The more fertilizer in the river, the more crops will grow along the river. b. The more chemical plants there are, the more chemical pollution that results. c. The more trash sent to the landfill, the higher the income of families in the region. d. The more sewage in the river, the greater the level of pollution.

50. Chickens lay varying numbers of eggs depending upon several factors. Which of the following is NOT a suitable testable hypothesis for a study of these factors? a. Chickens exposed to more hours of light will lay more eggs. b. Chickens which produce more eggs seem to lose weight. c. Chickens in larger cages produce more eggs. d. Chickens with more protein in their feed produce more eggs.