Significant Figures and Scientific Notation

1

• Measurement

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Measurement
Why
To get information about a subject.
There are 2 Types of Information

• Qualitative

Descriptive (no measured values)
e.g.

• cold, warm, hot
• near or far
• light or heavy

• Quantitative

Measured value
e.g.

• temperature (C, F, K)
• linear measure (m, ft, mile)
• weight (mass) (kg, tonnes, lbs)

3
Measurement Activity
Part I

• Transfer fluid from a wash bottle to a
  beaker.Measure as accurately as possible and
  record your value.
• Transfer fluid to a graduated cylinder, measure
  and record your value.
• Transfer fluid back into the wash bottle. Dry
  all glassware and put all equipment neatly away.

Part II

• Measure the nail with the centimeter scale as
  accurately as you can. Record the length and
  uncertainty.

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What is a measured value?

• A value assigned (given) to the subject when
  compared to a standard.

Two types of measurement

• Discrete counted values

e.g.

• Number of students in this class
• Number of eggs in a dozen

• Comparative a value from comparing with a
  standard

e.g.

• Length (2.52 m)
• Volume (15.86 mL)

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All comparative measurements have two parts

• value
• uncertainty

Expression of Value Uncertainty
The last digit of a comparative measurement is an
estimate and is uncertain.
Definitions
Accuracy
refers to how close the measured value is to the
accepted value.
Precision
refers to the uncertainty of a measurement. More
precise less uncertainty Less precise more
uncertainty
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• Assignment

• Classwork
• Scientific Notation worksheet
• Measuring worksheet
• Homework
• Finish Measuring worksheet