Table of Contents

1. Table of Contents • Measurement–A Common Language • Mathematics and Science • Graphs in Science • Safety in the Science Laboratory

2. - Measurement–A Common Language A Standard Measurement System • Using SI as the standard system of measurement allows scientists to compare data and communicate with each other about their results. SI units are based on multiples of 10.

3. - Measurement–A Common Language Length • The basic unit of length in the SI system is the meter (m).

4. - Measurement–A Common Language Mass • The basic unit of mass in the SI system is the kilogram (kg).

5. - Measurement–A Common Language Volume • Volume is the amount of space an object takes up.

6. - Measurement–A Common Language Density • Because density is actually made up of two other measurements–mass and volume–an object’s density is expressed as a combination of two units.

7. Suppose that a metal object has a mass of 57 g and a volume of 21 cm3. Calculate its density. Read and Understand What information are you given? Mass of metal object = 57 g Volume of metal object = 21 cm3 - Measurement–A Common Language Calculating Density

8. Suppose that a metal object has a mass of 57 g and a volume of 21 cm3. Calculate its density. Plan and Solve What quantity are you trying to calculate? The density of the metal object = __ What formula contains the given quantities and the unknown quantity? Density = Mass/Volume Perform the calculation. Density = Mass/Volume= 57 g/21 cm3 = 2.7 g/cm3 - Measurement–A Common Language Calculating Density

9. Suppose that a metal object has a mass of 57 g and a volume of 21 cm3. Calculate its density. Look Back and Check Does your answer make sense? The answer tells you that the metal object has a density of 2.7 g/cm3. The answer makes sense because it is the same as the density of a known metal–aluminum. - Measurement–A Common Language Calculating Density

10. Practice Problem What is the density of a wood block with a volume of125 cm3 and a mass of 57 g? 0.46 g/cm3 - Measurement–A Common Language Calculating Density

11. Practice Problem What is the density of a liquid with a mass of 45 g and a volume of 48 mL? 0.94 g/mL - Measurement–A Common Language Calculating Density

12. - Measurement–A Common Language Time • The second (s) is the SI unit to measure time.

13. - Measurement–A Common Language Temperature • In addition to the Celsius scale, scientists sometime use another temperature scale, called the Kelvin scale. The kelvin (K) is the official SI unit for temperature.

14. - Measurement–A Common Language Converting Between Units • Using the appropriate conversion factor, you can easily convert one unit of measurement to another. • This example shows how to convert 1.5 kilometers to meters.

15. - Measurement–A Common Language Comparing and Contrasting • As you read, compare and contrast different types of measurement by completing a table like the one below. Characteristic Length Mass Time Temperature Distance from one point to another Amount of matter Passing of events Hotness or coldness Definition Degrees of Celsius or Kelvin SI Unit Meter (m) Gram (g) Second (s) Measuring Tool Metric ruler Balance Watch or clock Thermometer

16. - Measurement–A Common Language More on Measurement • Click the PHSchool.com button for an activityabout measurement.

17. End of Section:Measurement– A Common Language

18. The area of a surface is the amount of space it covers. To find the area, multiply its length by its width. Remember to multiply the units as well. Area = Length x Width Suppose an area measures 12.0 m by 11.0 m. Area = 12.0 m x 11.0 m = 132 m2 Practice Problem Calculate the area of room 4.0 m long and 3.0 m wide. 4.0 m x 3.0 m = 12 m2 - Mathematics and Science Area

19. The area of a surface is the amount of space it covers. To find the area, multiply its length by its width. Remember to multiply the units as well. Area = Length x Width Suppose an area measures 12.0 m by 11.0 m. Area = 12.0 m x 11.0 m = 132 m2 Practice Problem Calculate the area of a ticket stub 5.1 mm long and2.62 mm wide. 5.1 mm x 2.62 mm = 13.4 mm2 (13, to the correct significant figure) - Mathematics and Science Area

20. - Mathematics and Science Accuracy and Precision • In order to hit the bull’s-eye consistently, you need both accuracy and precision.

21. - Mathematics and Science Significant Figures • The significant figures in a measurement include all of the digits that have been measured exactly, plus one digit whose value has been estimated.

22. - Mathematics and Science Significant Figures • When you multiply measurements, your answer can only have the same number of significant figures as the measurement with the fewest significant figures.

23. Read and Understand What information are you given? Experimental value = 9.37 g/cm3 True value = 8.92 g/cm3 You calculate the density of an object to be 9.37 g/cm3. The density of the object is actually 8.92 g/cm3. Calculate your percent error. - Mathematics and Science Percent Error

24. You calculate the density of an object to be 9.37 g/cm3. The density of the object is actually 8.92 g/cm3. Calculate your percent error. Plan and Solve What quantity are you trying to calculate? Percent error = __ What formula contains the given quantities and the unknown quantity? - Mathematics and Science Percent Error

25. Plan and Solve Perform the calculation. Percent Error = 5.04% - Mathematics and Science Percent Error You calculate the density of an object to be 9.37 g/cm3. The density of the object is actually 8.92 g/cm3. Calculate your percent error.

26. Look Back and Check The answer tells you that your percent error is about 5%. This answer makes sense because the experimental value and the true value were close to each other. - Mathematics and Science Percent Error You calculate the density of an object to be 9.37 g/cm3. The density of the object is actually 8.92 g/cm3. Calculate your percent error.

27. Tanya measured the mass of an object to be 187 g. Sam measured the object’s mass to be 145 g. The object’s actual mass was 170 g. What is Tanya’s percent error? 10.0% - Mathematics and Science Percent Error

28. Tanya measured the mass of an object to be 187 g. Sam measured the object’s mass to be 145 g. The object’s actual mass was 170 g. What is Sam’s percent error? 14.7% - Mathematics and Science Percent Error

29. - Mathematics and Science Mean, Median, and Mode • The mean is the numerical average of the numbers in a list.

30. - Mathematics and Science Mean, Median, and Mode • If an ordered list has an odd number of entries, the median is the middle number in a set of data. If a list has an even number of entries, the median is the sum of the two middle numbers divided by two.

31. - Mathematics and Science Mean, Median, and Mode • The mode is the number that appears most often in a list of numbers.

32. - Mathematics and Science Asking Questions • Before you read, preview the red headings. In a graphic organizer like the one below, ask a what, how, or why question for each heading. As you read, write the answers to your questions. Questions Answers What does estimation have to do with science? Scientists use estimation when they cannot obtain exact measurements. Accuracy refers to how close a measurement is to the true or accepted value, and precision refers to how close a group of measurements are to each other. What are accuracy and precision? What are significant figures? The term significant figures refers to the digits in a measurement. What is percent error? Percent error is a calculation used to determine how accurate an experimental value really is. What are mean, median, and mode? They are ways to calculate an “average.”

33. - Mathematics and Science Links on Math and Science • Click the SciLinks button for links on math and science.

34. End of Section:Mathematics and Science

35. - Graphs in Science The Importance of Graphs • Line graphs are used to display data to show how one variable changes in response to another variable. In this experiment, the responding variable is the time it takes for the water to boil. The manipulated variable is the volume of water in the pot.

36. - Graphs in Science Plotting a Line Graph

37. - Graphs in Science Plotting a Line Graph Activity • Click the Active Art button to open a browser window and access Active Art about plotting a line graph.

38. - Graphs in Science Why Draw a Line of Best Fit? • A line of best fit emphasizes the overall trend shown by all the data taken as a whole.

39. - Graphs in Science Slope • The slope of a graph line tells you how much y changes for every change in x.

40. - Graphs in Science Car Travel • The graph shows the distance a car travels in a one-hour period. Use the graph to answer the questions that follow.

41. Time (min), the manipulated variable, is plotted on the horizontal axis. Distance (km), the responding variable, is plotted on the vertical axis. Reading Graphs: What variable is plotted on the horizontal axis? What variable is plotted on the vertical axis? - Graphs in Science Car Travel

42. The car travels 10 km in10 minutes and 40 km in40 minutes. Interpreting Data: How far does the car travel in the first 10 minutes? In 40 minutes? - Graphs in Science Car Travel

43. The car is traveling 1 km per minute. It would travel 120 km in 120 minutes. Predicting: Use the graph to predict how far the car would travel in 120 minutes. Assume the car continues to travel at the same speed. - Graphs in Science Car Travel

44. The slope is 1 km/min. The slope provides information about the car’s average speed. Calculating: Calculate the slope of the graph. What information does the slope provide about the speed of Car 2? - Graphs in Science Car Travel

45. Drawing Conclusions: Compare the graphs for Car 1 and Car 2. What is the relationship between the steepness of the graph lines and the speed of the cars? The slope of the graph for Car 1 is 0.5 km/min. Because the distance and time values are marked the same on the two graphs, a steeper line represents a greater speed. Car 2 is traveling twice as fast as Car 1. - Graphs in Science Car Travel

46. - Graphs in Science Using Graphs to Identify Trends • Line graphs are powerful tools in science because they allow you to identify trends and make predictions.

47. Key Terms: Key Terms: Examples: Examples: slope coordinate nonlinear graph data point line of best fit linear graph - Graphs in Science Building Vocabulary • A definition states the meaning of a word or phrase by telling about its most important feature or function. After you read the section, reread the paragraphs that contain definitions of Key Terms. Use all the information you have learned to write a definition of each Key Term in your own words. Key Terms: Examples: graph The slope of a graph line is how steep the line is. A graph is a picture of data that reveals patterns or trends. A coordinate is a point on a graph that is determined by a pair of numbers. A nonlinear graph is a graph on which the data points do not fall on a straight line. horizontal axis A data point on a graph is where an imaginary line from the horizontal axis would meet an imaginary line from the vertical axis. The horizontal axis is the graph line that runs from left to right. vertical axis The vertical axis is the graph line that runs up and down. The line of best fit on a graph is a smooth line between points that reflects the general pattern of the points. origin The origin of a graph is the point where the horizontal and vertical axes meet. A linear graph is a straight-line graph.

48. End of Section:Graphs in Science

49. - Safety in the Science Laboratory Safety in the Lab • These safety symbols remind you to work carefully when performing labs in this textbook series. Make sure you are familiar with each safety symbol and what it means.

50. - Safety in the Science Laboratory In Case of an Accident • When any accident occurs, no matter how minor, notify your teacher immediately. Then listen to your teacher’s directions and carry them out quickly.