Chapter 1: Introduction to Science

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Chapter 1 Introduction to Science
1.1 The Nature of Science 1.2 The Way Science
Works 1.3 Organizing Data
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Vocabulary

• Scientific Notation
• Precision
• Significant figures
• Accuracy

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Line Graphs

• Line Graphs best for showing data that changes
• x-axis independent variable (bottom of graph)
• y-axis dependent variable (side of graph)

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Bar Graphs

• Bar Graphs useful for comparing data for several
  individual items
• Makes large or small differences in data very
  clear

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Pie Chart

• Pie Chart useful for displaying data that are
  parts of a whole
• Add up to 1 or 100

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Parts of a Graph

• Title of Graph
• Label axis/pie chart
• UNITS!
• All data
• Zero (on line and bar graphs)
• Set up EQUAL divisions

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Analyzing Data from Graphs

• Outliers data that is abnormally high or low
• Unusual or rare data
• Mean the average (add up all data points and
  divide by total number of data points)

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Analyzing Data from Graphs

• Median number in the middle when data is
  displayed from least to greatest
• Mode the data that shows up the most often

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Significant Figures (aka sig figs)

• Rules for Sig Figs
• Non-zero digits are ALWAYS significant
• Any zeros between sig figs ARE significant
• A final zero or trailing zero in the decimal
  portion ONLY are significant

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Sig Fig Examples

• How many sig figs are in each number?
• 3.0800
• 0.00418
• 7.09 x 10-5
• 91,600
• 0.003005
• 3.200 x 109
• 250
• 780,000,000
• 0.0101
• 0.00800

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Significant Figures in calculations

• When you , -, , or , your answer should only
  be as precise as the least precise measurement in
  the calculation

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Sig Figs

• Example A gummy bear has the dimensions of 1.34
  cm long, 0.82 cm wide, and 1.0 cm high. Find the
  volume of the gummy bear with the correct of
  sig figs. (Remember V l w h)

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Scientific Notation

• Why? So scientists can easily express numbers
  that are very large or very small.
• What? A simple number (1 or greater AND less than
  10) multiplied by a power of 10
• Examples
• 6.24 106
• 2.1 10-2

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Scientific Notation

• How?
• Using original number, move decimal so that the
  number is one or greater and less than 10.
• Count how many places the decimal was moved.

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Scientific Notation

• If the number you started with is greater than 1,
  the exponent is POSITIVE
• If the number you started with is less than 1,
  the exponent is NEGATIVE
• Scientific notation can be reversed to write the
  number in standard form again.

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Accuracy vs. Precision

• Accuracy how close a measurement is to the true
  value
• Precision how exact a measurement is