Precision, Uncertainty and Accuracy Not very precise!

Slides:



Advertisements
Similar presentations
Errors and Uncertainties in Biology Accuracy Accuracy indicates how close a measurement is to the accepted value. For example, we'd expect a balance.
Advertisements

Types of Numbers (Data)
Section 1: Significant Figures
Chapter 2 Section 3.
Significant figures or Significant digits
Using Scientific Measurements.
Ch. 3.1 – Measurements and Their Uncertainty
Measurements: Every measurement has UNITS.
Significant Figures (digits)
1 Significant Digits Reflect the accuracy of the measurement and the precision of the measuring device. All the figures known with certainty plus one extra.
Chapter 2: Scientific Measurement Ms. Campos
Uncertainty in Measurement
Significant Figures PP 6a Honors Chemistry.
The Mathematics of Chemistry Significant Figures.
Chapter 2 Data Handling.
Precision and Accuracy Uncertainty in Measurements.
Accuracy: The closeness of a measurement to the true or actual value
Lesson Starter Look at the specifications for electronic balances. How do the instruments vary in precision? Discuss using a beaker to measure volume versus.
Section 2.3 Measurement Reliability. Accuracy Term used with uncertainties Measure of how closely individual measurements agree with the correct or true.
Measurement book reference p Accuracy  The accuracy of the measurement refers to how close the measured value is to the true or accepted value.
Measurement and Its Uncertainties.
1 Parts of a Measurement 1.The value (numerical portion) 2.The unit (describes what units) 3.The name of substance being measured EX: 1 teaspoon salt 2.
Scientific Measurements “measurement” could be defined as the process or the result of determining the magnitude of a quantity. Measurements can be made.
3.1 SIGNIFICANT FIGURES The Concepts. Significant figures pertain to MEASUREMENTS.
Measuring Significantly Count significant digits because significant digits count!
© Copyright Pearson Prentice Hall Measurements and Their Uncertainty > Slide 1 of Using and Expressing Measurements A ___________________ is a quantity.
Accuracy, Precision, and Significant Figures in Measurement
Uncertainty in Measurement Accuracy, Precision, Error and Significant Figures.
Uncertainties for AH Phys. Accuracy and Precision The accuracy of a measurement tells you how close the measurement is to the “true” or accepted value.
Significant Figures Chemistry 10 Chemistry 10 Significant figures: the number of digits in an experimentally derived number that give useful information.
2.3 Using Scientific Measurements. Accuracy vs. Precision  Accuracy- closeness of measurement to correct or accepted value  Precision- closeness of.
Slide 1 of 48 Measurements and Their Uncertainty
Chapter 2 Measurements and Calculations Or It all adds up!
Preview Lesson Starter Objectives Accuracy and Precision Significant Figures Scientific Notation Using Sample Problems Direct Proportions Inverse Proportions.
“Scientific Measurement”. Measurements and Their Uncertainty OBJECTIVES: Convert measurements to scientific notation.
Measurements 1. A very concrete methods of dealing with the description and understanding of nature 2.
Measurement & Calculations Overview of the Scientific Method OBSERVE FORMULATE HYPOTHESIS TEST THEORIZE PUBLISH RESULTS.
All measurements are subject to uncertainties. All instruments used are influenced by external circumstances, and the accuracy of a measurement may be.
Chapter 3 Vocabulary Measurement Scientific notation.
Chemistry Chapter 2D Uncertainty in Measurement. Uncertainty  Represents how well a measurement was made  Science is ‘peer reviewed’  We don’t just.
Significant Figures and Scientific Notation. What is a Significant Figure? There are 2 kinds of numbers:  Exact: the amount of money in your account.
Section 2.3. Accuracy: the closeness of measurements to the correct or accepted value of the quantity measured Precision: the closeness of a set of measurements.
Measurements and Sig Figs. The Quality of Experimental Results Accuracy: how close a measured value is to the actual (true) value. Precision: how close.
Maths Skills. Uncertainties Use the smallest readable unit of instrument. Measuring length on a ruler eg. 1mm on ruler, uncertainty is mm.
What do you know about these words listed above?.
SOL Review 1.  Accuracy: measure of how close a measurement comes to the actual true value  Precision: measure how close a series of measurements are.
Section 2-3 Section 2.3 Uncertainty in Data Define and compare accuracy and precision. Describe the accuracy of experimental data using error and percent.
Accuracy, Precision and Significant Figures. Scientific Measurements All of the numbers of your certain of plus one more. –Here it would be 4.7x. –We.
Measurement: Significant Figures. Significant Figures  Significant Figures (sig. figs.): the number of digits that carry meaning contributing to the.
Significant Figures Show the Uncertainty in Measured Data
3.1 Measurements and Their Uncertainty Using and Expressing Measurements - A measurement is a quantity that has both a number and a unit. Scientific Notation.
Chemistry Using and Expressing Measurements Section 3.1.
Unit: Introduction to Chemistry
Using Scientific Measurements.
Significant Figures.
Measurements and Significant Figures
Introduction to Chemistry and Measurement
Significant Figures Show the Uncertainty in Measured Data
Using Scientific Measurements.
Measurements and Sig Figs
Measurements and Sig Figs
Chapter 2 Accuracy vs Precision.
Significant Figures.
Measurement Unit Unit Description:
Measurement book reference p
Accuracy and Precision
Significant Figures (digits)
Accuracy and Precision
Measurements and Their Uncertainty 3.1
Presentation transcript:

Precision, Uncertainty and Accuracy Not very precise!

Precision, Uncertainty and Accuracy +/- 0.1 g +/ g +/ g

Very Precise (Analytical) Balance Uncertainty = +/ g

Precision -The number of significant digits to which a value has been reliably measured. -The more decimal places, the more precise the measurement. -The greater the precision, the less the uncertainty.

Uncertainty -How much a measurement from an instrument can vary during a measurement. -Usually expressed as +/- ( eg / g means the measured mass could be between and g.) -The smaller the uncertainty, the more precise the measurement -Readings must be written to the number of dec. places which reflect the uncertainty of the instrument. ( eg would be OK for a balance with an uncertainty of +/ g or would be OK for a balance with an uncertainty of +/ g)

Accuracy The accuracy of a measurement is how close the measurement is to an accepted standard. (eg. a “standard” or “calibration” weight which comes with a new balance)

Significant Digits (Figures) The number of significant digits in a measurement is the number of certain digits plus one more (with some uncertainty) For the measurement g Certain digitsUncertain This measurement has ____ significant digits.