CHM 109 Lecture Notes - Lecture 2: Hexa, Nonmetal, Aluminium Oxide
Document Summary
Accuracy and precision are terms used to describe measurements accuracy means how close to the true answer a measurement is precision means how close repeated measurements of the same thing are. 3. 5 significant figures applies only to measurement instruments with more markings (divisions) are said to be more precise sig figs are a means of controlling measured numbers so that they do not imply more information than the measurements actually have. All the known digits plus one estimated digit and the unit. 2178. 9 cm has 5 sig figs: zeros in the middle of non-zeros are sig ex. 1006. 25 s has 6 sigs: zeros to the left of non-zero digits are not sig ex. Lefties (ppl who are left handed) are insignificant : zeros to the right depend on where the decimal is. 120 m has 2 sigs, use 1. 20 x 10 2 m to make 120 m have 3 sigs. 12. 00 m has 4 sigs, 120. 1 m has 4 sigs.
