CHEM 131 Chapter Notes - Chapter 2: Substance Dependence, Thermal Energy, Intensive And Extensive Properties
2 Dec 2015
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2. 1 the metric mix-up: a million unit error. Quantification is the assignment of a number to some property of a substance or thing (ex: a 16cm pencil) On dec 11, 1998, nasa launched the mars climate orbiter. A unit mix-up caused the orbiter to enter mars" atmosphere at an altitude too low. The reliability of a measurement depends on the instrument used to make the measurement (a butcher scale is more precise than a bathroom scale) more digits = more certainty less digits = less certainty. Scientific measures are reported so that every digit is certain except for the last, The number of digits reported depends on the measuring device. 10. 5g on one scale is 10. 4977 on another. There are two kinds of certainty in science: accuracy how close the measurement is to the actual value, precision how close a series of measurements are to one another.
