CH 101 Study Guide - Final Guide: Kilogram, Ampere, Significant Figures

• School: University of Alabama
• Department: Chemistry
• Course: CH 101
• Professor: Jared M.Allred

Document Summary

Units are quantities used to specify measurements, which are critical in chemistry: the two most common unit systems are: Metric system- used in most of the world. English system- used in the united states: scientists use the international system of units (si), which is based on the metric system. Accuracy refers to how close the measured value is to the actual value: measurements are accurate only if they are close to the actual value. Precision refers to how close a series of measurements are to one another or how reproducible they are: measurements are precise if they are consistent with one another. Scientific measurements are reported so that every digit is certain with the exception of the last digit, which is estimated. Significant figures deal with writing numbers to reflect precision: the precision of a measurement depends on the instrument used to make the measurement, the preservation of this precision during calculations can be accomplished by using significant figures.