CHEM103 Chapter Notes - Chapter 1.5: Decimal Mark, Significant Figures, Scientific Notation

• School: University of Alberta
• Department: Chemistry
• Course: CHEM103
• Professor: John Veinot

Document Summary

Chapter 1 keys to the study of chemistry. We always estimate the rightmost digit of a measurement. The uncertainty can be expressed with the sign, but generally we drop the sign and assume an uncertainty of one unit in the rightmost digit. All digits are significant, except zeros used only to position the decimal point. If there is a decimal point and the zeros lie either after or before it, they are significant: 1. 1300 g has 5 sig-figs, and 6500. A terminal decimal point indicates that zeros are significant: 500ml has 1 sig-fig, but 500. ml has 3. Exact numbers have no uncertainty associated with them. E. g. there are exactly 60 minutes in 1 hour. Precision: or reproducibility refers to how close the measurements in a series are to each other. Accuracy: refers to how close each measurement is to the actual value. Systematic error: produces values that are either all higher or all lower than the actual value.